3 Weeks Pregnant Is How Many Months?

"Pregnancy Weeks to Months" Calculator

3 Weeks Pregnant Is How Many Months?

Answer

3 Weeks Pregnant is

less than one obstetric month

First trimester

Obstetric months and calendar months

Doctors count in obstetric months of exactly four weeks. By that count 3 Weeks is less than one obstetric month.

A calendar month averages 30.4375 days, so the same term is about 0.69 calendar months. The two counts never agree, and by the end of a term they differ by 0.8 of a month: 40 weeks are 10 obstetric months and 9.2 calendar ones.

About "Pregnancy Weeks to Months" Calculator

Pregnancy is counted in completed weeks from the first day of the last menstrual period, and a full term is 40 weeks or 280 days — that is Naegele's rule. Enter a term in weeks and the calculator says which obstetric month it falls into, which trimester it belongs to, how many weeks are left and when the estimated due date is.

An obstetric month is exactly four weeks, which is why 40 weeks make ten obstetric months but only about nine calendar ones. Both numbers are printed on every page, because the two counts disagree and the disagreement is what the question is usually about.

This is an arithmetic tool, not medical advice. The due date it prints is an estimate; only a doctor can set the real term.

"Pregnancy Weeks to Months" Calculator

Pregnancy Weeks and Months Table

Weeks of Pregnancy	Obstetric Months	Trimester
1 Week	less than one obstetric month	First trimester
2 Weeks	less than one obstetric month	First trimester
3 Weeks	less than one obstetric month	First trimester
4 Weeks	1 obstetric Month	First trimester
5 Weeks	1 obstetric Month and 1 Week	First trimester
6 Weeks	1 obstetric Month and 2 Weeks	First trimester
7 Weeks	1 obstetric Month and 3 Weeks	First trimester
8 Weeks	2 obstetric Months	First trimester
9 Weeks	2 obstetric Months and 1 Week	First trimester
10 Weeks	2 obstetric Months and 2 Weeks	First trimester
11 Weeks	2 obstetric Months and 3 Weeks	First trimester
12 Weeks	3 obstetric Months	First trimester
13 Weeks	3 obstetric Months and 1 Week	First trimester
14 Weeks	3 obstetric Months and 2 Weeks	Second trimester
15 Weeks	3 obstetric Months and 3 Weeks	Second trimester
16 Weeks	4 obstetric Months	Second trimester
17 Weeks	4 obstetric Months and 1 Week	Second trimester
18 Weeks	4 obstetric Months and 2 Weeks	Second trimester
19 Weeks	4 obstetric Months and 3 Weeks	Second trimester
20 Weeks	5 obstetric Months	Second trimester
21 Weeks	5 obstetric Months and 1 Week	Second trimester
22 Weeks	5 obstetric Months and 2 Weeks	Second trimester
23 Weeks	5 obstetric Months and 3 Weeks	Second trimester
24 Weeks	6 obstetric Months	Second trimester
25 Weeks	6 obstetric Months and 1 Week	Second trimester
26 Weeks	6 obstetric Months and 2 Weeks	Second trimester
27 Weeks	6 obstetric Months and 3 Weeks	Second trimester
28 Weeks	7 obstetric Months	Third trimester
29 Weeks	7 obstetric Months and 1 Week	Third trimester
30 Weeks	7 obstetric Months and 2 Weeks	Third trimester
31 Weeks	7 obstetric Months and 3 Weeks	Third trimester
32 Weeks	8 obstetric Months	Third trimester
33 Weeks	8 obstetric Months and 1 Week	Third trimester
34 Weeks	8 obstetric Months and 2 Weeks	Third trimester
35 Weeks	8 obstetric Months and 3 Weeks	Third trimester
36 Weeks	9 obstetric Months	Third trimester
37 Weeks	9 obstetric Months and 1 Week	Third trimester
38 Weeks	9 obstetric Months and 2 Weeks	Third trimester
39 Weeks	9 obstetric Months and 3 Weeks	Third trimester
40 Weeks	10 obstetric Months	Third trimester
41 Weeks	10 obstetric Months and 1 Week	Third trimester
42 Weeks	10 obstetric Months and 2 Weeks	Third trimester

3 Weeks Pregnant Is How Many Months