I didnt put DD on her tummy, but once she could roll, thats just what she did herself and she slept much better that way. I still lay her down on her back, but she will always roll onto her tummy to go to sleep. DH was really worried when he first saw her do it and tried to get me to keep putting her back on her back, but i figured if she could get herself there, she could get herself out of trouble. She always turns her head to the side too, so i was never worried.

I think seeing as babies are little people, they have their own idea about what is comfy and how they like to have things!! If belly is working go with it, but for a young bub if your concerned maybe look into a sensor monitor to be extra careful!