Anyone else experiencing diarrhea while taking Metformin? Will be 7 weeks pregnant tomorrow. I know diarrhea is a normal side effect of Metformin, and normal during pregnancy, I'm just concerned I am going to get dehydrated.  I took it prior to becoming pregnant and was ok, but since becoming pregnant I'm having diarrhea at least 3-4 times a day. This has been going on for a few weeks now. Any suggestions or insight would be greatly appreciated!