What to Expect During Each Trimester of Pregnancy

Learn what to expect during each month of your pregnancy

Pregnancy is an exciting time when your body goes through many changes. Your growing baby also goes through a rapid series of changes as they grow from a cluster of cells into the baby that you get to welcome into the world.

The average pregnancy lasts about 40 weeks, although it is normal to deliver with the range of 2 weeks before or after this date. These weeks are also broken up into trimesters that all include a specific set of symptoms and stages of development. Learning more about the stages of pregnancy month-by-month helps you to know how to take care of yourself and your baby for a healthy delivery.

First Trimester (Weeks 1-12)

A woman may not realize she is pregnant until well into her first trimester. This is especially the case if a woman does not have regular menstrual cycles. During the first trimester, your body is dealing with many hormonal changes that can affect other body functions and organs.

Some common symptoms women in their first-trimester experience include:

  • Fatigue
  • Nausea
  • Vomiting
  • Mood swings
  • Tender and/or swollen breasts
  • Heartburn
  • Headaches
  • Weight gain or loss
  • Need to urinate more often

Most of these symptoms will dissipate as the pregnancy progresses. You may experience one, all or none of these symptoms. Each woman is different, and so is each pregnancy. What you experience during your first pregnancy may be totally different from your second.

Nausea is the most common issue women deal with during the first trimester. Typically, women are advised to eat small meals of low fat and non-greasy food, drinking plenty of liquid and wearing a motion sickness armband.

Check out this week-by-week breakdown of most things you can expect during your first trimester.

Weeks 1 and 2: You might be surprised to find that the first 2 weeks of your pregnancy timeline actually took place before you were even pregnant. During these 2 weeks, your body prepares for pregnancy by completing the last menstrual cycle and ovulating.

Week 3: This is a big week for your pregnancy. At this point, your body releases an egg and conception is possible. Once conception occurs, your zygote begins its first stage of fetal development. This includes the formation of the spinal cord and brain.

Week 4: By now, you might be noticing that you are late for your next menstrual cycle, although this might not occur until next week or later. You might also be beginning to feel symptoms from your increasing pregnancy hormones.

Week 5: This is the time during your pregnancy timeline when you might see a positive pregnancy test. This is also the best time to arrange for your first prenatal appointment to make sure that everything is going normally.

Week 6: Those hormones are beginning to show up now. Morning sickness is common during this stage. You might also have breast soreness, headaches and feel more tired than normal. Your little baby is also almost an inch long.

Week 7: Your baby is hard at work growing all of their vital organs. This week, they are also starting to grow their tiny arms.

Week 8: Congratulations! Your baby has now progressed from being an embryo to a fetus. They also have recognizable facial features.

Week 9: Morning sickness and fatigue may still be going strong right now, but your little one is currently developing their reproductive organs. Boy or girl? You still can’t tell, but it won’t be long now!

Week 10: Your baby has now completely lost its tail, which has been replaced by 2 legs.

Week 11: At almost 2 inches, you can’t feel your baby yet, but you can bet that they are wriggling around.

Week 12: This signals the end of your first trimester. You should notice your early pregnancy symptoms easing up.

Second Trimester (Weeks 13-27)

Many women find that they begin to feel better during the second trimester. Often, the nausea and fatigue from the first trimester ends or is not as severe. However, the second trimester brings about many other physical changes, such as:

  • Increased breast size — Breast tenderness should subside at this point, but they will probably grow due to preparing for milk production. A supportive bra may be necessary.

  • Weight gain and growing belly — A normal weight gain during the second trimester is 3 to 4 pounds a month as your abdomen begins to expand. If you were overweight to begin with, your pregnancy care doctor or midwife may caution you on the weight gain.

  • Vaginal discharge
  • Braxton Hicks contractions — This is when your uterus begins contracting to prepare for the baby and can begin in the second trimester. They are usually very weak and not painful. Contact your physician if the pain gets worse to make certain you are not experiencing pre-term labor.

  • Leg cramps — These usually occur at night and can get worse as you get further into the pregnancy.

  • Kidney and bladder infections

This is a rough overview of symptoms to expect, but the week-by-week breakdown below goes more into detail.

Week 13: Most women’s risk of miscarriage decreases in the second trimester. If you haven’t done so already, go ahead and start making your pregnancy announcement.

Week 14: Your pregnancy symptoms might have eased up, but you still need to make time for self-care. Rest and make sure to continue going to those vital prenatal care appointments.

Week 15: During this week or soon, your doctor might conduct tests to check for Down syndrome and other chromosomal disorders.

Week 16: Your blood volume has increased. This can result in that pregnancy glow, along with the higher possibility of having nosebleeds.

Week 17: Your baby’s hair, eyebrows and eyelashes are growing in.

Week 18: You might be starting to feel some little tummy flutters as your baby gets big enough to feel. If not, don’t worry. Some moms feel movement closer to the 20-week mark.

Week 19: Now that your baby’s vital parts are formed, they’ll begin adding layers of fat underneath their skin.

Week 20: You’ve made it halfway! Go ahead and sing a celebratory song to your baby. They can hear you now.

Week 21: By now, you are noticeably pregnant to others. You might also notice a few stretch marks that show how much your tummy is growing.

Week 22: Boy babies are beginning to have their testicles descend now. It won’t be much longer before you can get a real gender reveal with an ultrasound.

Week 23: Your baby’s lungs are starting to practice breathing now.

Week 24: This is the week of viability when most babies could survive with serious medical intervention.

Week 25: Have you felt the baby’s hiccups yet? These little bubbles are perfectly normal.

Week 26: Testing for gestational diabetes often occurs around this time.

Week 27: You may start to see your OB/GYN every 2 weeks now.

Third trimester (weeks 28-40)

You've made it this far and now the arrival of your baby is just weeks away! First, though, here is what you may experience:

  • Backaches — At this point, you are carrying much more weight than your body is accustomed to. The pressure on your back with this extra weight can cause back discomfort.

  • Difficulty sleeping — It can be tough to get comfortable sleeping during these last weeks of pregnancy. One recommendation is to sleep on your side and use a pillow between your legs.

  • Continued Braxton Hicks contractions

  • Frequent urination

  • Bleeding — If you see bleeding, do not panic. Call your physician so they can examine you to make sure that it is nothing serious.

  • Heartburn and constipation

  • Hemorrhoids

  • Shortness of breath

  • Swelling of feet

For further insight into this last trimester, continue reading.

Week 28: By this week, you might be feeling pretty familiar with the pregnancy stages and symptoms, but keep going strong with your healthcare regimen.

Week 29: Those baby movements are getting more intense. Did they just kick a rib?

Week 30: Your growing tummy can throw your sense of balance off. Make sure to guard against falls.

Week 31: Braxton Hicks contractions might begin.

Week 32: Talk to your doctor at your next visit about the signs of preterm labor.

Week 33: Your baby’s bones are hardening up.

Week 34: You may be asked to start kick counts now by your doctor.

Week 35: Shortness of breath, fatigue and mild anxiety are all normal pregnancy symptoms.

Week 36: Your obstetrician might start checking to see if the baby’s head is down yet to prepare for birth.

Week 37: Now’s a great time to finalize your birth plan with your physician.

Week 38: Once-a-week visits to your doctor are common at this stage in the pregnancy.

Week 39: Your baby’s arrival is expected at any moment.

Week 40: Double-check the car seat and make sure your bags are packed. This week marks the final one in the pregnancy trimester breakdown. Congratulations on making it this far towards bringing your baby home!

Every pregnancy is different, but there are marked milestones that help you and your pregnancy care doctor know when everything is going right. Take care of yourself and enjoy this time. Feeling those little first kicks and seeing your baby on the ultrasound are moments that you’ll never forget.

If you have any questions about your pregnancy, be sure to reach out to our trusted staff at All About Women right here in North Florida.

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