I've been on the same brand of prenatal vitamins every day since I was 4 weeks pregnant. Never had any trouble until about 3 weeks ago I would get a tummy ache and diarrhea that was yellow/orange 1-3 times a day. At first I figured my body was changing and I was becoming lactose intolerant...nope. I made an appointment for it with my primary & it's coming up...I skipped my prenatal and no tummy ache. But this morning I took it and had the same problem as before, diarrhea...has anyone gotten a tummy ache and diarrhea from their prenatal vitamins??