I wouldn't worry about it I had even asked doc he said for first few months it was OK to sleep onmy back it becomes more of risk the further you are along .
Yeah it's very rarely I will roll and stay lied on my back it was the first since Iv been pregnant. I normally sleep on my left side
I normally sleep on my side but being pregnant on the back seems to help me fall asleep but I am constantly moving from one position to the next.
Probably just from pressure
It could be dangerous to sleep on your back constantly due to the major vein that runs through your stomach being squished by baby. When your baby lies on the vein it prevents proper blood flow and it could cut off their oxygen. It's ok to lie on your back once in a while, but if you can avoid it even better!
I have the same issue! My little princess makes it uncomfortable to get into any position.
I wake up on my back often and have the same aches when I get up. It's mostly because you have so much added pressure on your back and spine and it somewhat restricts your bloodflow from what I've heard. But you should be fine :)
I do this all the time don't worry about it, you would move in your sleep naturally if it was uncomfy/baby was distressed