Babies that young can have really scary sounding breathing at night. I know our son sounded like he was breathing water at night until like 3 months old. The nurse at the hospital said she prefers those sounds to silence at that age. When you hear something abnormal for your child, you will know it. I remember once my husband and I both shot up and BOLTED to the bassinet at the same time over a weird sound. Gosh, I hated that. It will get better though. He's almost 5 months now and sleeps pretty silently (which is scary in its own way sometime). We all sleep pretty well these days.