your not supposed to cause there is a main artery running thru the bottom of your back and they said after 4 months ur uterus is to heavy and cuts off some of the blood flow to ur heart which affects ur baby to
I slept on my back during my first pregnancy and I do it during this pregnancy and nothing bad has resulted from it. I don't do it all the time but who can honestly sleep on their side all night every night? I have woken up so sore from sleeping on my side too much. My muscles literally would ache on whatever side I had been sleeping on if I slept that way for too long.
i try to sleep on my sides every night and like you it hurts my hips and back. every morning i wake up on my back and it freaks me out (i'm only 21 weeks)
i swear after i get off of my back my heart starts pounding for a while but maybe it's in my head. i don't know...