Your Pregnancy Week by Week: A Complete Guide
Pregnancy is an incredible 40-week journey of growth and transformation. Understanding what happens at each stage helps you prepare, stay healthy, and bond with your developing baby long before delivery day.
First Trimester (Weeks 1–12)
The first trimester is a period of rapid cellular development. By week 6, your baby’s heart begins to beat. By week 12, all major organs have formed and your baby is about the size of a lime.
- Weeks 1–4: Implantation occurs. You may not yet know you’re pregnant. Start taking prenatal vitamins with folic acid.
- Weeks 5–8: Morning sickness may begin. Your baby’s brain, spinal cord, and heart are forming rapidly.
- Weeks 9–12: Fingers and toes develop. Your first ultrasound typically happens around week 12, confirming your due date.
Second Trimester (Weeks 13–26)
Often called the “golden trimester,” most parents feel more energetic during this phase. Your baby begins to move, and you can usually find out the sex around week 20.
- Weeks 13–16: Baby can make facial expressions. You may start feeling light fluttering movements (quickening).
- Weeks 17–20: The anatomy scan at week 20 checks for structural development. Baby is now about the size of a banana.
- Weeks 21–26: Baby responds to sounds and light. Lungs are developing but not yet mature enough for breathing.
Third Trimester (Weeks 27–40)
The final stretch focuses on weight gain and lung maturation. Your baby’s brain develops rapidly, and practice breathing begins.
- Weeks 27–30: Baby can open and close eyes. Kicks become stronger and more regular.
- Weeks 31–36: Baby moves into a head-down position. You should start counting kicks daily.
- Weeks 37–40: Baby is considered full-term at week 39. Pack your hospital bag and finalize your birth plan.
Track Your Pregnancy Milestones
Use our Pregnancy Due Date & Milestones Calculator to find your estimated delivery date, see a week-by-week countdown, and track key development milestones personalized to your pregnancy.