What to Expect Each Trimester: A Due Date-Based Timeline

Pregnancy is an incredible journey — and knowing what to expect each trimester can help you feel more confident and prepared. Whether you've just found out or you're counting down the weeks, this guide breaks down what’s happening with you and your baby in each phase of pregnancy.

👶 First Trimester (Week 1–12)

🧬 What's Happening

• Baby’s major organs begin forming
• Heartbeat can be detected by week 6–8
• Placenta starts to develop

🩺 What to Expect

• Positive pregnancy test
• Morning sickness, fatigue, food aversions
• First prenatal visit and bloodwork
• Possibly your first ultrasound

Tip: Use your due date to estimate how far along you are today.

🤰 Second Trimester (Week 13–27)

🌱 What's Happening

• Baby develops facial features and starts moving
• You might feel “quickening” (baby kicks!) around week 18–20
• Baby can hear sounds by week 24

🩺 What to Expect

• More energy and less nausea
• “Anatomy scan” ultrasound around week 20
• Baby bump becomes more visible
• Start wearing maternity clothes

Note: This is often considered the most comfortable phase of pregnancy.

🤱 Third Trimester (Week 28–40+)

🚼 What's Happening

• Baby gains most of its weight
• Lungs and brain finish developing
• Baby begins to position head-down for birth

🩺 What to Expect

• More frequent prenatal checkups
• Swelling, back pain, and sleep changes
• Prepping for labor — hospital bag, birth plan, etc.
• Labor signs: contractions, water breaking

⏱ Countdown Tip

Remember, only 5% of babies are born exactly on their due date. Your pregnancy is full term anywhere from 37 to 42 weeks.

📌 Final Thoughts

Each trimester brings new changes and emotions. Understanding your timeline helps you stay informed and proactive — from prenatal care to baby gear prep.

Want to know how far along you are? Try our Pregnancy Due Date Calculator to track your progress.