Silly question, Does trimester 2 starts at week 13 or 14. Very confusing. Some say 13, some say 14.

Trimester 2 starts from week 14. Some months of pregnancy have have 5 weeks. You can refer to the attached picture on the breakdown :)

I was confused as well. Google shows different answer. Pregnancy is 40 weeks. Divide by 3 trimester is about 13.33333333.

Trimester 1 - week 1 to week 12 Trimester 2 - week 13 to 26 Trimester 3 - week 27 to week 40