My daughter wouldn’t sleep well on her back at all. Slept her on her side for a while. She didn’t like to be swaddled and if she would sleep on her back it wasn’t for long because she jumped at every small thing. So she has mostly always slept on her tummy

See I have a 4 week old baby girl and that’s the only why she sleeps is on her belly and it scares me

When my baby was like a month and a half he’d sleep on his belly never had any issues. That’s the earliest he slept on his belly