When does the second trimester start?

Week 14 is the start of the second trimester. Week 28 is the start of the third.

Full term is 40 weeks. So divide by 3, and each trimester is 13.33 weeks. If you want the real number, it’s simple! But people estimate and say either 13 or 14. It also varies based on what country you’re in how many weeks they declare “full term” (40, 39, 41) and that can change the number. It’s not an exact science, and it doesn’t need to be! Each baby follows their own growth timeline

I went from 13th week for second and 28w for third xx

I was told it’s week 13 xx