Stomach sleeping

Ca

My LO is 11 weeks old but she has been flipping to her stomach since she was about 7 weeks old. She was swaddled then snd I figured she was just kind of rolling over since she was so rounded in the swaddle. So we started using a transitional sleepsack so she could have her arms freer in case she rolls again. She didn’t roll again for a few days. But then she did. The thing is I don’t think she can quite roll over from tummy to back yet. I know that’s very opposite of most kids. She hasn’t been able to figure out how to use her arm strength to help. She can get to her side with a lot of effort but that’s about it. Usually I will turn her back onto her back if I see her on her tummy but inevitably when I go in for nighttime feeds or in the morning she’s on her belly. Just now I fed her, put her down, she grunted and complained while I cleaned pumping equipment. Then I went to check on her and she was on her belly. I turned her over and walked back to my room, checked the monitor, and in that time she had flipped again! So the point is she’s really into sleeping on her stomach. I think tomorrow we will start using a real sleep sack and not the transitional one. But should I be concerned since she can’t flip herself onto her back? Or at least I don’t think she can. I worry a lot about SIDS and I know putting a baby to sleep on his/her back is a huge part of SIDS prevention