Pregnancy Week by Week Choose your gestational age and learn more about what is happening inside you. FIRST TRIMESTER 1 WEEK 2 WEEK 3 WEEK 4 WEEK 5 WEEK 6 WEEK 7 WEEK 8 WEEK 9 WEEK 10 WEEK 11 WEEK 12 WEEK 13 WEEK SECOND TRIMESTER 14 WEEK 15 WEEK 16 WEEK 17 WEEK 18 WEEK 19 WEEK 20 WEEK 21 WEEK 22 WEEK 23 WEEK 24 WEEK 25 WEEK 26 WEEK 27 WEEK THIRD TRIMESTER 28 WEEK 29 WEEK 30 WEEK 31 WEEK 32 WEEK 33 WEEK 34 WEEK 35 WEEK 36 WEEK 37 WEEK 38 WEEK 39 WEEK 40 WEEK 41 WEEK 42 WEEK