So I haven't been constipated this pregnancy and in fact had a BM this morning already... But usually when I get my period I get a day or so of pretty painful cramps that get especially bad before I use the toilette. So what is going on with my body right now! To add to the confusion, I just ran out of my regular vitamins and yesterday I took one with some iron in it (just 6 mg). Usually I take no iron (my levels are fine and it doesn't sit well with me). I am 37 weeks 2 days.