Changes in Your Body During Pregnancy: First Trimester


What is the first sign of pregnancy?

A missed period is usually the first sign of pregnancy. You may also have some mild cramping and a little bleeding when the fertilized egg implants itself in your uterus.

If you’ve missed your period and think you may be pregnant, you can try a home pregnancy test. These tests are very accurate if you take them a few days after you expected to get your period.

Your doctor can confirm your pregnancy and talk to you about prenatal care.

Why do I feel so tired?

Feeling very tired is one of the most common symptoms of early pregnancy. Your body is working hard to adjust to being pregnant. This can cause extreme fatigue. You may need to sleep longer than usual at night and take short naps during the day, if possible. Your energy will most likely return in the second trimester of pregnancy.

What is morning sickness?

Morning sickness is the nausea and vomiting that many pregnant women experience during the first few months of pregnancy. Morning sickness is caused by pregnancy hormones and can happen anytime, not just in the morning. Certain foods or smells might make you feel sick and sometimes vomit. Some women seem to feel sicker when their stomachs are empty.

Morning sickness usually starts a few days after you miss your period or have a positive pregnancy test. It usually goes away by the second trimester.

Other changes in the first trimester

Frequent urination. Towards the end of the first trimester, you will feel like urinating more often as your growing uterus pushes on your bladder. You may leak a little urine when you cough or sneeze because of the extra pressure on your bladder.

A growing belly. Your waistline will begin to expand as your baby and your uterus grow larger. Depending on your size before pregnancy, you may not notice this change until the second trimester.

Emotional symptoms. You might feel moody, forgetful, or unable to concentrate. Tiredness, pregnancy hormones, and the emotions that can go along with being pregnant can cause these symptoms.

Lightheadedness. Your body is working overtime to make extra blood to support your growing baby. This can cause you to feel dizzy or lightheaded. Hunger, weakness, or stress can also cause these symptoms.

Heartburn. Pregnancy hormones slow down the process of breaking down food in order to give your body more time to absorb nutrients. Some of the muscles in your body that break down food are more relaxed and food stays in your stomach longer, which may cause heartburn.

Constipation. The slow process of breaking down food can also cause constipation, gas, and bloating. You should be taking a prenatal vitamin that contains iron. The iron in the vitamin can also lead to constipation. Your doctor may suggest taking fiber supplements or a stool softener to help with constipation. You should also make sure you are drinking plenty of water (about eight glass per day). If you have severe problems, tell your doctor. He or she may want you to take a different prenatal vitamin.

Visible veins. The blue veins in your belly, breasts, and legs may become more noticeable as your body makes extra blood and your heart pumps faster to meet the needs of pregnancy. You may develop spider veins—tiny blood vessels radiating out from a central area, like the legs of a spider—on your face, neck or arms.

Skin changes. Other people may notice your "pregnancy glow," which is the rosy, shiny look your skin gets from increased blood circulation. Pregnancy hormones can cause some extra oil on your skin, which might spark a temporary flare-up of acne.

Breast changes. Many women notice changes in their breasts early in pregnancy. The hormones in your body are changing to prepare for breastfeeding. As these changes occur, your breasts may feel tender and swollen. You might also notice some small bumps forming in the area around your nipples. Your breasts will continue to grow and change throughout your pregnancy, and may feel even bigger and fuller later in pregnancy.

Vaginal changes. The lining of your vagina will become thicker and less sensitive. You may notice a thin, whitish discharge, which is normal during pregnancy. Mild vaginal bleeding (“spotting”) is also common and normal. However, you should call your doctor if you have any vaginal bleeding. If the bleeding is severe or painful, go to the emergency room.

Written by editorial staff

Reviewed/Updated: 10/15
Created: 10/09