Pregnancy Symptoms By Trimester

A woman holding a positive pregnancy test

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From morning sickness to mood swings, pregnancy brings about a wide variety of changes. Factors like hormonal shifts, increased blood volume, stress, and more can lead to the physiological signs and symptoms we associate with expecting a baby. 

Still, everyone’s experience of pregnancy is different. Everyone won’t expect the same symptoms or the same physical and emotional changes.

Read on for the typical pregnancy symptoms to expect in each trimester, as well as when you should talk to a healthcare provider about potential complications.

How Early Do Pregnancy Symptoms Start?

Soon after an embryo implants in your uterus, the pregnancy starts producing human chorionic gonadotropin (hCG), also known as the "pregnancy hormone." Your progesterone and estrogen levels will also rise as your body supports the early pregnancy. As the pregnancy progresses, almost all of your hormones — including insulin, stress hormones like cortisol, and thyroid hormones — will be affected.

These hormonal changes begin at the time of ovulation and fertilization, but become more pronounced after implantation and as the pregnancy progresses. Some people may notice some signs of pregnancy as early as 4-6 weeks, which is around the time of their first missed period or a few weeks later. 

However, you might not notice symptoms until much later. This doesn’t necessarily mean that you aren’t pregnant or that anything is wrong.

First Trimester Symptoms

For many people, the first sign of pregnancy is a missed period, usually around 2 weeks after ovulation.

Implantation bleeding, which typically occurs around 6-12 days after conception, can sometimes be confused with a light menstrual period. Implantation bleeding is slight vaginal spotting or bleeding that can happen when the fertilized egg implants in the uterus. Only around 25% of pregnant people experience this early sign of pregnancy. 

Other symptoms of pregnancy during the first trimester (weeks 1-12) of pregnancy may include:

  • Fatigue
  • Breast tenderness
  • Nausea
  • Vomiting
  • Heartburn
  • Headache
  • Frequent urination
  • Changes in weight, whether up or down
  • Constipation
  • Food cravings
  • Food aversions
  • Mood swings
  • Sensitivity to certain smells
  • Vaginal discharge
  • Larger breasts
  • Prominent nipples
  • Bloating
  • Gas

Second Trimester Symptoms

Many people experience a welcome reprieve from symptoms like nausea and vomiting during the second trimester of pregnancy (13-28 weeks). However, as your body grows to accommodate your growing baby, you may notice other physical changes. 

These can include: 

  • Backache
  • Darker nipples
  • Muscle pain
  • A line running down your abdomen from your belly button, known as the linea nigra
  • Stretch marks
  • Tingling or numbness in the hands or fingers
  • Swollen ankles, face, feet, or fingers
  • Increased appetite
  • Itchy abdominal area
  • Brown patches of skin on your face (melasma)
  • Feeling the baby move

Third Trimester Symptoms

During the third trimester (weeks 29-40), your body starts gearing up for labor and delivery. With looser joints and a much larger baby putting pressure on your internal organs, you might feel like you don’t move around as easily as you used to. 

Here are some common symptoms during the third trimester:

  • Heartburn
  • Urinating more often
  • Swollen feet and ankles
  • Hemorrhoids
  • Insomnia
  • Swollen, tender breasts
  • Belly button “popping” inside out
  • Milky discharge (colostrum) coming from the breasts
  • Shortness of breath
  • Feeling the baby drop down further into your pelvis (lightening)
  • Uterine contractions

When To See a Healthcare Provider About Your Symptoms

It’s normal to experience a wide variety of physical and emotional symptoms during pregnancy. Most are nothing to worry about. 

However, some symptoms may pose a risk to you or your baby. Seek medical attention right away if you experience any of the following during pregnancy:

  • Abnormal or heavy bleeding
  • Severe, unusual headaches
  • Heart palpitations
  • Tremors 
  • Seizures
  • Signs of infection
  • Vision problems
  • Dizziness
  • Severe abdominal pain
  • Uterine cramping or contractions
  • Amniotic fluid leakage
  • Difficulty urinating
  • Difficulty breathing
  • High fever
  • Lack of fetal movement
  • Severe swelling

Health Complications to Watch Out For

There are a few health complications every expecting person should be aware of.

Ectopic Pregnancy

An ectopic pregnancy is a potentially life-threatening situation in which a fertilized egg starts to grow outside of the uterus (usually in one of the fallopian tubes). If the tube ruptures, you may need emergency surgery to save your life. Symptoms of ectopic pregnancy typically develop during the first trimester. Signs can include lower back pain, unusual vaginal bleeding, abdominal pain, severe pain in the pelvic area (especially on one side in particular), pain in the shoulder, dizziness, weakness, and lightheadedness.

Hyperemesis Gravidarum

Nausea and vomiting are common during the first trimester. But if you can’t keep food down or throw up many times a day, you may have hyperemesis gravidarum, a disorder that may require hospitalization and treatment with intravenous (IV) fluids and/or medications.


Preeclampsia is a serious pregnancy complication that involves symptoms of liver or kidney damage and hypertension (high blood pressure) after 20 weeks. Symptoms include blurry vision, infrequent urination, vomiting, headache, trouble breathing, pain on the upper right side of the abdomen, sudden weight gain, swelling, and feeling faint. 

HELLP Syndrome

HELLP syndrome is a type of preeclampsia that usually develops during the third trimester. It involves hemolysis (red blood cell destruction), elevated liver enzymes, and a low platelet count. Signs include headache, weight gain, swelling, bloating, vision problems, stomach pain, excessive bleeding, seizures, nausea, headache, and a general sense of illness and fatigue.

A Quick Review

Thanks to factors like hormonal changes, increased stress levels, and alterations in eating and sleeping habits, pregnancy leads to a number of physical changes. 

During the first trimester of pregnancy, you may experience symptoms like fatigue, nausea, vomiting, breast tenderness, headaches, heartburn, and frequent urination. Some people start to notice stretch marks, backache, and fetal movement during the second trimester, followed by swollen feet, insomnia, and shortness of breath in the third trimester. 

However, everyone’s pregnancy is different. You may experience all of these symptoms or very few. Talk to your healthcare provider about any physical changes that concern you. Go to the hospital or talk to your OB-GYN right away if you notice unusual vaginal bleeding or if you feel extremely unwell.

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  2. Eunice Kennedy Shriver National Institute of Child Health and Human Development. What are some common signs of pregnancy?.

  3. Eunice Kennedy Shriver National Institute of Child Health and Human Development. What are some common signs of pregnancy?.

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  6. The American College of Obstetricians and Gynecologists. Changes during pregnancy.

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  8. MedlinePlus. Hyperemesis gravidarum.

  9. MedlinePlus. Preeclampsia.

  10. MedlinePlus. HELLP syndrome.

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