First Trimester Pregnancy Symptoms Week by Week

Your body experiences a wide range of changes throughout pregnancy, from symptoms like breast tenderness in the first trimester to backaches in the third. For parents-to-be, these pregnancy-related symptoms can be expected or surprising. Your body is going through a lot of changes during pregnancy, and every person’s experience is different. This list of pregnancy symptoms by week can help prepare you for what might be on the horizon, but don’t worry if your pregnancy doesn’t follow this precise timeline. Much like life and the new baby you’re welcoming, pregnancy can be unpredictable. Of course, if you have questions or concerns about your symptoms, talk to a prenatal health care provider.

Have you been wondering what to expect as your pregnancy progresses? Here’s a list of the most common pregnancy symptoms, week by week. Be sure to talk with your doctor if you have any concerns.

Week 1

Since doctors calculate your due date from the first day of your last period, week one begins with the start of the last period you have before you conceive. That’s to say that you are not technically pregnant yet. You can, however, expect to experience your typical menstrual symptoms including bleeding, cramping, sore breasts, mood swings, etc.

Week 2

Ovulation typically occurs during what’s considered week two. Your ovary will release a mature egg that travels into the fallopian tube, where it awaits fertilization with sperm. Symptoms of ovulation can include twinging lower abdominal pain (mittelschmerz), breast tenderness, slippery discharge that resembles egg whites, and increased basal body temperature.

Week 3

During week three, the fertilized egg implants into the uterine lining. Some people experience mild abdominal cramping or light spotting known as “implantation bleeding.” Call your doctor if you’re bleeding heavily or have intense pain; this could indicate an ectopic pregnancy where the embryo implanted outside of the uterus (usually in the fallopian tube).

Week 4

Your at-home pregnancy test can come back positive as early as this week—congratulations! Breast tenderness, one of the earliest signs of pregnancy in some people, might make your bra feel extra uncomfortable at this time. Some also experience a heightened sense of smell or taste, fatigue, constipation, bloating, and mood swings. But don’t worry if you don’t have any pregnancy symptoms at all; they might take a few extra weeks to show up.

Week 5

Hormone-induced mood swings can bring on a lot of feelings starting at week five. Your emotions may change from happy to depressed to angry for no conceivable reason. Other early pregnancy symptoms—like fatigue, breast tenderness, and even nausea—can kick in this early too.

Week 6

For some, week six brings one of the most dreaded symptoms: morning sickness (although it may start further along in your pregnancy or not at all). Your heightened sense of smell can further exacerbate this queasiness, which sets the stage for food cravings and aversions. Morning sickness might stick around until the second trimester, so it’s best to find ways to cope now, such as eating smaller meals, consuming ginger, wearing acupressure wristbands, and avoiding triggering foods.

Week 7

Frequent urination is another early pregnancy symptom. It’s caused by a few factors: the pregnancy hormone hCG, increased fluids in your body, your kidneys working extra hard to eliminate waste, and eventually, your growing uterus compressing your bladder. Plan for plenty of bathroom breaks!

Week 8

For many, pregnancy symptoms appear in full force by now: nausea, breast tenderness, fatigue, frequent urination, mood swings, bloating, etc. Another unusual symptom is extra saliva in your mouth, which sometimes lasts until the end of the first trimester. Headaches are also common thanks, in part, to hormonal surges.

Week 9

Did you know that pregnancy can affect your digestive system? Pregnancy hormones can change the motility of your intestines, leading them to move more slowly than usual. Many people experience constipation and excess gas, in addition to the nausea that accompanies morning sickness. Plus, as your baby grows, the more your digestive system slows, so talk to your doctor about stool softeners if needed.

Week 10

Are you glowing? Some people will experience a radiant “pregnancy glow” in the first trimester, but it’s also common to experience hormone-induced acne. You’ll also notice your breasts—and your belly—getting bigger each week.

Week 11

Your growing baby bump might cause aches and cramping around your abdomen. This round ligament pain can be mildly uncomfortable or downright painful. You might also notice a clear or creamy discharge (known as leukorrhea) in your underwear that signals your body is attempting to clear bacteria, which is a normal during pregnancy.

Week 12

Did you know that blood volume increases by about 50 percent during pregnancy? One side effect is visible veins on the skin, which are especially noticeable in lighter-skinned people.

Week 13

As you near the end of the first trimester, many early pregnancy symptoms will diminish. You might start to notice, however, that you feel dizzy throughout the day. You can thank hormonal shifts, reduced blood flow, and lower blood pressure for these dizzy spells. Combat them by taking deep breaths with your head between your knees and changing positions slowly.

Week 14

You’re officially in the second trimester of pregnancy, which most deem to be the “easiest” trimester. Many people report increased appetite, renewed energy, and higher sex drive during the next few weeks. If that’s you, take advantage of this “feel good” trimester by starting a doctor-approved fitness routine and preparing your house for baby.

Week 15

The second trimester can also come with a few strange symptoms. You might experience a stuffy nose (thanks to an increase of blood in the mucus membranes), leg cramps, and sensitive gums. As the hormone relaxin loosens your ligaments, you might also feel extra clumsy at this stage of pregnancy.

Week 16

About 90 percent of pregnant people experience a darkening of the skin around the nipples, inner thighs, armpits, and navel. Sometimes the darkening extends to the cheeks and nose (known as “the mask of pregnancy”)—especially if you have a darker complexion.

Week 17

Backaches are very common while expecting (you can thank pregnancy hormones yet again!). And if you’re feeling more forgetful than normal, blame the so-called “pregnancy brain” that many experience. As a plus, many expectant parents start feeling their baby kick between weeks 16 to 25, so be on the lookout!

Week 18

By now, your belly likely looks pregnant—and your breasts have begun to increase in size to prepare for making breast milk. Expect to gain weight regularly until delivery (usually about 1 pound per week). Stretch marks might appear as well, anywhere from to your stomach to your hips and breasts. Even foot size can increase during pregnancy!

Week 19

During the second trimester, some pregnant people experience heartburn. This is because pregnancy hormones relax the muscles of your lower esophageal sphincter (LES). If you experience this uncomfortable symptom, try eating smaller meals, staying upright after eating, and avoiding anything acidic, greasy, or spicy. Constipation might also occur as your baby presses against your intestines.

Week 20

By now, your little one might be kicking up a storm! The first kicks feel like fluttering in your stomach. Also common during this time are leg cramps, swelling in the hands and feet, dry eyes, varicose veins, and trouble sleeping. If you haven’t already, try using a pregnancy pillow for a better night’s rest.

Week 21

Although you might’ve had round ligament pain for a while, it tends to increase as the baby grows. You may feel sharpness in your hip, groin, and abdomen as they stretch to accommodate your growing uterus. Your uterus can also put pressure on your lungs, causing shortness of breath.

Week 22

Pregnancy often results thicker, shinier hair and fast-growing nails thanks to increased progesterone and your body stocking up on extra nutrients (so don’t forget to continue taking your prenatal vitamin). You might notice your locks feel stronger and more bountiful than usual. But you might also get dry, irritated skin on your stomach, since it’s constantly being stretched.

Week 23

Your ever-growing belly can turn an “innie” belly button into an “outie,” but rest assured it will return to its normal state after delivery. During this time, you’ll probably continue dealing with leg cramps, brain fog, backaches, increased vaginal discharge, constipation, headaches, stretch marks, and other second trimester pregnancy symptoms.

Week 24

While some pregnant people still have a high sex drives, others notice a dwindling libido. They might feel too sore and tired to do the deed. Other pregnancy symptoms include tingling hands and bleeding gums, as well as snoring from swollen membranes and pregnancy weight gain.

Week 25

Do your hands and fingers feel tingly? You may be experiencing carpal tunnel syndrome, which when experienced during pregnancy, is often a result of normal swelling and fluid retention. This numb sensation should go away after you give birth. In the meantime, avoid sleeping on your hands, and try shaking out your wrists throughout the day.

Week 26

Sleep might not come easily as you near the third trimester, whether it’s because of anxiety, leg cramps, frequent urination, or general discomfort. You might also experience itchiness in your hands and feet. Mild itchiness is usually benign, and it can be treated with antihistamines, ointments, or calming lotions. Intense itching, however, could signal a liver disorder called cholestasis of pregnancy that requries medical care.

Week 27

As if backaches and leg cramps weren’t bad enough, some people get hemorrhoids during the second trimester. These itchy, swollen veins pop up in the rectum because of increased blood flow and pressure, and they can get worse with the straining that often accompanies constipation. Relieve hemorrhoid pain and bleeding with ice packs, sitz baths, or witch hazel pads.

Week 28

Welcome to the third trimester! As you near the finish line, you may start feeling physically exhausted and generally uncomfortable. Aches and pains are commonplace, and some will have symphysis pubis dysfunction (SPD), which happens when the ligaments around the pubic bone become soft and unstable.

Week 29

As your body prepares to feed your baby after birth, you might notice yellowish colostrum leaking from your breasts. This fluid serves as a precursor to mature breast milk, and it helps your little one’s body adjust to life outside the womb.

Week 30

If you have experienced itchiness, swelling, aching, and heartburn, it probably hasn’t subsided yet. If you have stretch marks like the majority of pregnant people, they are probably getting more pronounced as well. These red, pink, purple, or even dark brown streaks can’t be prevented—in fact, they are usually genetically-determined—but they’ll fade significantly with time.

Week 31

Perhaps you were thrilled to put first trimester pregnancy symptoms behind you, but now some of them might make a comeback. For some people, they may have never left. For example, your breasts may become tender again as they start producing colostrum; you’ll likely need to pee frequently because of the pressure of your uterus against your bladder; and you may become extremely exhausted after only minimal effort. Hang in there.

Week 32

After 20 weeks of pregnancy, your body might produce “practice” contractions called Braxton Hicks. They’re characterized by a sporadic hardening or tightening of the uterus—and they come more often as the pregnancy progresses. Braxton Hicks contractions usually last between 30 seconds and two minutes, and they’ll stop if you change positions. While Braxton Hicks are expected, call your doctor if you experience contractions that get stronger and more frequent, as that can be a sign of premature labor.

Week 33

Your baby is getting bigger, and they’re still pressing against your internal organs. The result? The potential for a leaky bladder, shortness of breath, heartburn, and general discomfort.

Week 34

You’re getting closer to delivery, but remember: Every day counts for your baby’s development during the last few weeks of pregnancy, so you’ll want to let your baby continue growing as long as it’s medically safe. You may notice some decreased movement as your baby grows and gets into position for birth, but always contact your doctor if you have any concerns or notice significantly less movement.

Week 35

As labor quickly approaches, you’ll notice more regular Braxton Hicks contractions. Make sure you know how to differentiate these practice pains from actual contractions. Your weight gain might also begin to plateau around week 35, and many people find that insomnia comes in full force.

Week 36

Your little one is on the move! About two to four weeks before delivery, your baby will begin “dropping” into your lower pelvis (also called lightening or engagement). This move may take some pressure off your internal organs, allowing you to breathe easier.

Week 37

Your little one’s new position might lead to pelvic discomfort and increased abdominal pressure. You might notice a little spotting after sex, but you shouldn’t worry: This is probably a result of your sensitive, enlarged cervix. Call your doctor if you’re bleeding heavily, though, since this could indicate problem with the placenta.

Week 38

Around week 37 or 38, most pregnant people lose their mucus plug. The mucus plug blocks the opening to your your cervix to protect your baby from germs. It typically gets released anywhere from a few days to a couple of weeks before labor, and it looks like thick pink or blood-tinged discharge.

Week 39

If your water breaks, you may notice a gush of fluid or a slow trickle. Other early signs of labor include regular contractions, pelvic pressure, dull back pain, and a feeling of restlessness. Early labor tends to last for hours. Many doctors recommend that first-time parents wait this phase out and head to the hospital when contractions come every four or five minutes, last for one minute, and continue in this pattern for an hour (the 4-1-1 or 5-1-1 rule), but your provider may have a different recommendation for you.

Week 40

You’ll likely keep experiencing pregnancy symptoms like insomnia, swelling, frequent urination, and pelvic discomfort until your baby arrives. If you’ve scheduled an induction or C-section, it may happen within the next few days or weeks.

Week 41

After 40 weeks, your baby is considered “overdue” as they’ve passed their due date, but in most cases, this is perfectly fine and it’s actually quite common. Even so, an overdue baby can cause some anxiety and restlessness, but hang in there and watch for signs of labor. Your little one will be here soon!

Week 42

Most babies are born within two weeks of their due date (before or after), so while reaching week 42 might be exhausting, it’s not uncommon. If your doctor is concerned, they may recommend inducing labor. In the meantime, continue to take care of yourself—your baby will be in your arms before you know it.

How Much Does a Baby Grow In A Week First Trimester

Your baby’s growth in the first trimester is quite exciting. As you move into your second month, you might be wondering how much your baby will have grown by then. Because fetal growth may be on a different timetable, this can vary from one pregnancy to another. The good news is that you’ll also notice some of these changes in your body

The average baby weighs a few ounces in the third week of the first trimester. By the seventh week your fetus will weigh almost one pound and is about 12 inches long. At one month, your little bundle of joy weighs about half a pound (220 grams) and measures 5.1 inches from crown to rump. During the first trimester, it’s still very difficult to detect any signs of pregnancy through external means, so you may not notice any marked changes in your body size.

What is Normal in The First Month Of Pregnancy

Pregnancy is divided into 3 trimesters. Each trimester is a little longer than 13 weeks. The first month marks the beginning of the first trimester.

What’s gestational age?

Pregnancy timing is measured using “gestational age.” Gestational age starts on the first day of your last menstrual period (LMP).

Gestational age can be confusing. Most people think of pregnancy as lasting 9 months. And it’s true that you’re pregnant for about 9 months. But because pregnancy is measured from the first day of your last menstrual period — about 3-4 weeks before you’re actually pregnant — a full-term pregnancy usually totals about 40 weeks from LMP — roughly 10 months.

Many people don’t remember exactly when they started their last menstrual period — that’s OK. The surest way to find out gestational age early in pregnancy is with an ultrasound.

What happens during week 1 – 2?

These are the first 2 weeks of your menstrual cycle. You have your period. About 2 weeks later, the egg that’s most mature is released from your ovary — this is called ovulation. Ovulation may happen earlier or later, depending on the length of your menstrual cycle. The average menstrual cycle is 28 days.

After it’s released, your egg travels down your fallopian tube toward your uterus. If the egg meets up with a sperm, they combine. This is called fertilization. Fertilization is most likely to occur when you have unprotected vaginal sex during the 6 days leading up to — and including the day of — ovulation.

What happens during week 3 – 4?

The fertilized egg moves down your fallopian tube and divides into more and more cells. It reaches your uterus about 3–4 days after fertilization. The dividing cells then form a ball that floats around in the uterus for about 2–3 days.

Pregnancy begins when the ball of cells attaches to the lining of your uterus. This is called implantation. It usually starts about 6 days after fertilization and takes about 3–4 days to be complete.

Pregnancy doesn’t always happen, even if an egg is fertilized by a sperm. Up to half of all fertilized eggs pass out of your body when you get your period, before implantation is complete.

What are the signs of pregnancy?

For a lot of people, the first sign of pregnancy is a missed period. Most pregnancy tests will be positive by the time you’ve missed your period. Other early pregnancy symptoms include feeling tired, feeling bloated, peeing more than usual, mood swings, nausea, and tender or swollen breasts. Not everyone has all of these symptoms, but it’s common to have at least 1 of them.

Why Am I Showing In My First Trimester

In the first trimester, your body is going through a lot. Between adjusting to your changing hormones and managing all of the new physical symptoms of pregnancy, it can be hard to know what is normal and what is actually a big deal. Our experts have designed this kit to help you track your baby’s development, understand your own health and wellness in pregnancy, identify potential problems early enough for treatment before they become symptoms, and manage common complaints that can lead to complications in pregnancy. The First Trimester app includes an interactive video anatomy lesson from our renowned OB-GYN Dr. Erlanger Slocombe as well as our expert-created symptom checker that helps you understand what might be real or serious enough to call your doctor about–and quickly access important phone numbers for location-based care near where you live.

A pregnant woman sitting on the couch looking at a sonogram and the BabyCenter app.

Photo credit: Katie Rain for BabyCenter

If it’s your first pregnancy, or even if it isn’t, you may be wondering when your bloated belly will turn into a baby bump, and your pregnancy will start to show. The short answer: It can be different for everyone, for a number of reasons.

When do you start showing in pregnancy?

First-time moms usually start showing sometime between 12 and 18 weeks. In a BabyCenter poll, most women expecting their first child said they started to show between 12 and 18 weeks, very closely followed by those who said that their bump emerged between 18 and 24 weeks.

Every woman and every baby bump is different, and there isn’t an exact time when you’ll start “showing,” which is what happens when your growing uterus begins to expand above the pubic bone. This usually starts when you’re around 12 weeks pregnant; before then, the uterus remains within the pelvis and isn’t usually visible.

Even at 12 weeks of pregnancy, any “bump” you start to see in your abdomen is really just your bowels that used to be in your pelvis, now being pushed up higher in your belly. “Showing” starts as your abdomen looks fuller and you find yourself needing to unbutton your pants by the end of the day. From there, a distinctly uterus-shaped bump will appear in another few weeks or so.

Several factors play a part in how and when you start showing:

  • Your body shape and size. Shorter women may start showing earlier than tall women, and thinner women may see a distinct baby bump before plus-size women do.
  • Your core muscles. Women with weak core muscles may start showing earlier than those with a stronger core.
  • The position of your uterus.
  • Whether not this is your first pregnancy. Moms who’ve already been pregnant often start showing with their second pregnancy sooner, since their uterine and abdominal muscles have been stretched from an earlier pregnancy.

Sometimes, you might think you’re already showing early on in the first trimester, but it’s more than likely just pregnancy bloating, a swelling that can make your pants fit tighter. Bloating is one of the early signs of pregnancy, along with gas and constipation.

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Should I be worried if I haven’t started showing yet?

If you haven’t started showing and feel like you don’t look pregnant yet, don’t fret. There are a number of completely normal factors that may be contributing to how pregnant you look. Showing late doesn’t automatically mean that your baby is too small. In the second trimester, your ob-gyn or midwife will start monitoring your fundal height to track your baby’s growth, and if there’s any reason for concern, they’ll do an ultrasound to check on the progress. Babies who are smaller than expected for their gestational age will get frequent monitoring to make sure they’re doing well.

Can You Start Showing in The First Trimester

If it’s your first pregnancy, you’ll probably start to show between 12 to 16 weeks, around the start of your second trimester. But this initial bump is not from the baby. In fact, at 15 weeks, the average fetus is 4 inches long, or about as large as an orange. 

So that “baby bump” isn’t from the baby’s size, but rather the expansion of your uterus.

“As the uterus gets bigger with a developing pregnancy, the loops of bowel which fill the abdomen are pushed upwards and out to the sides,” says Meg Wilson, MBBS, an OB-GYN at London Gynaecology.

What causes some to show early in pregnancy?

There are a few factors that might affect when you start showing: 

  • Height: If you have a short abdomen, your bump will likely pop out sooner than for taller women with a longer abdomen. “Women who have a long abdomen may have more space for their uterus to develop upwards rather than outwards, which can give the appearance of a smaller bump,” Wilson says.  
  • Weight: If you’re smaller with less body fat, you’ll probably show much earlier than someone with more body fat. 
  • Multiple buns in the oven: If you’re carrying twins or multiples, you’re more likely to show earlier — as early as 6 weeks. That’s because your uterus will expand more to create space for the additional fetuses. 
  • Not your first rodeo: You’re more likely to show early if this isn’t your first pregnancy.  “The uterus is held in position at the front by the abdominal walls: skin and muscle strength,” says Wilson. “For women who have had several pregnancies, the skin and muscle become weaker and the pregnant uterus can fall forward more.”

How doctors track baby bump progression

By week 20, your doctor will start measuring your fundal length — that’s the distance between the pubic bone and the top of the uterus. Typically, this number should correlate with your week of pregnancy.

So, for example, if your fundal length is 25 centimeters, you should be in or near your 25th week of pregnancy. 

If, however, your fundal length is too high, it could indicate growth problems with the baby, like fetal macrosomia, which is when a baby is significantly too large. 

On the flip side, if your fundal length is too low it could mean restricted growth, which is when the baby isn’t large enough. While not all small babies suffer from restricted growth, it’s worth checking in with your maternal health practitioner if you are concerned. 

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