3rd TrimesterMonth 9Week 39 of 40
39 Weeks Pregnant
— How Many Months Is It?
39w
Equivalent to
Month 9
3rd Trimester
🍉
Baby is the size of a
Watermelon
50.7 cm (~20 in) · 3.3 kg
🌱Fetal Development Milestones — Week 39
Brain and lung maturation continues until labor begins naturally.
Pregnancy timeline progress98%
Week 1Week 39Week 40
Calculate Your Exact Due Date
Enter your last period date for an instant gestational calculation
212835
Enter your date to calculate gestational age.
Based on ACOG guidelines and Naegele's Rule for informational purposes only. Consult your OB-GYN.
Adjacent Pregnancy Weeks
Frequently Asked Questions — Week 39
39 weeks pregnant equals Month 9 of gestation in the 3rd Trimester. Because calendar months vary between 28 and 31 days while weeks are exactly 7 days, clinical tracking in weeks provides the most accurate timeline.
Brain and lung maturation continues until labor begins naturally.
Use the calculator above: enter the first day of your last period (LMP) and the tool will calculate your exact estimated due date using Naegele\'s Rule (LMP + 280 days).