Pregnancy Symptoms Week by Week: Full Guide

Understanding your pregnancy symptoms week by week helps you know what is normal, what to watch for, and when something needs medical attention. Every pregnancy is different, but most women follow a recognizable pattern of symptoms across all 40 weeks.

This guide walks you through exactly what to expect in each trimester, backed by data from ACOG, Mayo Clinic, and other trusted medical sources. You can also track your symptoms and milestones with MyBumpGuide's weekly tracker.

First Trimester Symptoms (Weeks 1-13)

The first trimester is when your body undergoes the most dramatic hormonal shifts. According to the American College of Obstetricians and Gynecologists (ACOG), rising levels of hCG and progesterone drive most early pregnancy symptoms.

Weeks 1-4: Before You Know

Most women do not notice symptoms until after a missed period. During weeks 1 through 4, the fertilized egg implants in the uterine lining.

• Light spotting (implantation bleeding) in about 25% of pregnancies
• Mild cramping similar to period cramps
• Breast tenderness or swelling
• Fatigue due to rising progesterone

Weeks 5-8: Symptoms Kick In

This is when pregnancy symptoms week by week become unmistakable. By week 6, most women experience nausea. According to the Cleveland Clinic, about 70-80% of pregnant women experience some form of morning sickness during this window.

• Nausea and vomiting (morning sickness)
• Heightened sense of smell
• Food aversions or cravings
• Frequent urination
• Mood swings
• Extreme fatigue

Weeks 9-13: The Peak

Symptoms often peak around weeks 9 to 11. The NHS reports that fatigue and nausea are most intense during this period, but typically begin to ease by week 13.

• Nausea may be at its worst
• Visible veins on breasts and abdomen
• Slight weight gain (or loss from nausea)
• Bloating and constipation
• Increased vaginal discharge

Second Trimester Symptoms (Weeks 14-27)

Many women call the second trimester the "honeymoon phase." Morning sickness usually subsides, energy returns, and the baby bump begins to show.

Weeks 14-17: Relief Begins

By week 14, hCG levels plateau. According to Mayo Clinic, most women notice a significant improvement in nausea and fatigue during this window.

• Nausea fading
• Energy returning
• Growing appetite
• Round ligament pain (sharp pains on the sides of the abdomen)
• Nasal congestion from increased blood volume

Weeks 18-22: Movement and Growth

You will likely feel your baby's first movements (quickening) between weeks 18 and 22. ACOG notes that first-time mothers often feel movement closer to week 20-22, while experienced mothers may notice it earlier.

• Baby kicks and flutters
• Backaches
• Leg cramps
• Skin changes (linea nigra, melasma)
• Stretch marks beginning
• Swelling in hands and feet

Weeks 23-27: Preparing for the Third Trimester

During weeks 23 through 27, the uterus is now well above the belly button.

• Braxton Hicks contractions (practice contractions)
• Heartburn and indigestion
• Hemorrhoids
• Difficulty sleeping
• Shortness of breath

Third Trimester Symptoms (Weeks 28-40)

The final stretch brings its own set of pregnancy symptoms week by week. The baby is growing rapidly, putting increasing pressure on your organs.

Weeks 28-32: Getting Bigger

By week 28, the baby weighs about 2.5 pounds. According to March of Dimes, the third trimester is when most weight gain occurs for both mother and baby.

• Increased back pain
• More frequent Braxton Hicks
• Swollen ankles and feet
• Frequent urination returns
• Difficulty breathing deeply
• Trouble sleeping

Weeks 33-36: The Home Stretch

During weeks 33 to 36, the baby begins to settle into a head-down position.

• Pelvic pressure
• Lightning crotch (sharp nerve pains)
• Increased vaginal discharge
• Fatigue returns
• Nesting instinct
• Leaking colostrum

Weeks 37-40: Ready for Birth

From week 37 onward, the baby is considered early term. You may notice signs that labor is approaching.

• Lightening (baby drops lower into the pelvis)
• Mucus plug discharge
• Increased Braxton Hicks
• Diarrhea or loose stools
• Burst of energy (nesting)
• Water breaking

Pregnancy Symptoms Week by Week: Trimester Comparison Table

Symptom	First Trimester	Second Trimester	Third Trimester
Nausea/Vomiting	Peaks weeks 8-11	Usually resolves	Rare
Fatigue	Severe	Improved	Returns
Back Pain	Mild	Moderate	Severe
Breast Changes	Tenderness, swelling	Darkening areolas	Colostrum leaking
Braxton Hicks	None	Begin weeks 20+	Frequent
Baby Movement	None	Starts weeks 18-22	Very active
Heartburn	Occasional	Moderate	Often severe
Frequent Urination	Yes	Eases mid-trimester	Returns strongly
Swelling	Minimal	Mild	Often significant
Mood Changes	Intense	Stabilizing	Variable

When to Call Your Doctor

Most pregnancy symptoms are normal, but some require immediate medical attention. ACOG recommends contacting your provider if you experience:

• Vaginal bleeding or fluid leaking
• Severe abdominal pain
• Sudden swelling in the face or hands
• Severe headaches with vision changes
• Decreased fetal movement after week 28
• Contractions before 37 weeks
• Fever above 100.4 degrees Fahrenheit

How to Track Your Pregnancy Symptoms

Keeping a record of your symptoms helps you spot patterns and gives your healthcare provider valuable information at appointments. MyBumpGuide's week-by-week tracker lets you log symptoms, mood, and milestones from week 1 all the way through week 40.

Use our pregnancy calculator to find your exact week and start tracking today.

Frequently Asked Questions

What week do pregnancy symptoms start?

Most women notice their first symptoms between weeks 4 and 6, typically starting with a missed period, breast tenderness, and fatigue. Nausea usually begins around week 6. However, some women report feeling different as early as the week after conception.

What is the hardest trimester for symptoms?

For most women, the first trimester is the hardest due to intense nausea, fatigue, and hormonal upheaval. According to a study cited by the NHS, about 80% of women experience nausea in the first trimester, with symptoms peaking around weeks 8-11.

Do pregnancy symptoms come and go?

Yes, it is completely normal for symptoms to fluctuate. You may feel very nauseous one day and fine the next. According to ACOG, symptom variation is normal and does not typically indicate a problem. However, a sudden and complete disappearance of all symptoms in the first trimester should be mentioned to your doctor.

When do pregnancy symptoms get better?

Most early pregnancy symptoms (nausea, extreme fatigue, food aversions) improve significantly by weeks 13-14, at the start of the second trimester. Third trimester symptoms like back pain and swelling tend to resolve after delivery.

Can you have no symptoms and still be pregnant?

Yes. According to the Cleveland Clinic, some women experience very few or no noticeable symptoms, especially in early pregnancy. Lack of symptoms does not mean anything is wrong with the pregnancy.

Sources

1. American College of Obstetricians and Gynecologists (ACOG). "How Your Fetus Grows During Pregnancy." acog.org
2. Mayo Clinic. "Pregnancy week by week." mayoclinic.org
3. Cleveland Clinic. "Morning Sickness (Nausea and Vomiting of Pregnancy)." clevelandclinic.org
4. National Health Service (NHS). "Common symptoms in pregnancy." nhs.uk
5. March of Dimes. "Common discomforts of pregnancy." marchofdimes.org