Newborn sleep

KR

I know doctors/nurses tell us back to sleep, tummy for play but I also know some people do the opposite. With my first daughter we began putting her to sleep on her tummy at 3 weeks. My daughter now is 11 days and she can't seem to sleep well with being swaddled or with the jump reflex being free. She also burps really good after each feeding (brrastfed) but still manages to spit up in her sleep. Her laying on her back and me not hearing her spit up while I'm sleep terrifies me. Suggestions for sleeping her on her stomach this early?? To soon?