24 weeks light spotting

Tara

So when I first found out I was pregnant I had light spotting and it was always after a BM or intercourse. I went to my OB everything checked out fine she just suggested I take colace 1x a day and that my cervix was probably just irritated. Everything was fine until about 2 weeks ago, I called my doctor because I had been having a little itching and some spotting she called in a 7 day treatment for yeast infection didn't have any spotting while on the meds. Yesterday I went for my 24 week check up, everything was fine, urine sample was clean. This morning I woke up and had a little spotting AGAIN. So far just once when I've been to the bathroom. Could this be from sleeping on my back? (I start out on my side and always wake up on my back) or could it be from a BM I had yesterday? This is my 3rd pregnancy and I've never had these issues. Baby is also very low when kicking around.