2nd TrimesterMonth 5Week 21 of 40
21 Weeks Pregnant
— How Many Months Is It?
21w
Equivalent to
Month 5
2nd Trimester
🥕
Baby is the size of a
Carrot
26.7 cm (~10.5 in) · 360g
🌱Fetal Development Milestones — Week 21
Your baby regularly swallows amniotic fluid, practicing digestive and swallowing reflexes.
Pregnancy timeline progress53%
Week 1Week 21Week 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 21
21 weeks pregnant equals Month 5 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.
Your baby regularly swallows amniotic fluid, practicing digestive and swallowing reflexes.
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).