Grunting and pushing

I've seen tons of people talking about their babies doing the same but nothing that helped or no doctors comments on what it might be, my baby girl 2 weeks old is alwaays grunting and pushing sometimes she will grunt and push then fart and pass right out after her tummy is not hard she does cry from it sometimes but other times she pushes and grunts then nothing and right back to sleep she does this awake and asleep if doesn't wake her, but does worry me