2nd TrimesterMonth 4Week 15 of 40
15 Weeks Pregnant
— How Many Months Is It?
15w
Equivalent to
Month 4
2nd Trimester
🍎
Baby is the size of a
Apple
10 cm (~4 in) · 70g
🌱Fetal Development Milestones — Week 15
Fine hair (lanugo) starts growing on the scalp and body. The skeletal system is hardening.
Pregnancy timeline progress38%
Week 1Week 15Week 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.
Frequently Asked Questions — Week 15
15 weeks pregnant equals Month 4 of gestation in the 2nd 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.
Fine hair (lanugo) starts growing on the scalp and body. The skeletal system is hardening.
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).