I am a tummy sleeper as well and talked to my MW about it while pregnant.
She is also a tummy sleeper. She just said that whatever is comfortable for you to sleep then do it! Suggestions for tummy sleepers is to lie on your side with a one leg bent and a pillow under that leg and that should be quite comfortable, this is how I sleep normally minus the pillow so that was all comfortable for me. I found sleeping on my hips and side uncomfortable from about 34weeks this is when it all became too hard lol