Grunting at night

My 2 and half week old has been sleeping 7 hours a night since the third night we took him home which has been amazing! However the last two nights he has been restless and grunting while he is sleeping. It doesn’t necessarily wake him up but he makes noises all night long.

I do breastfeed and pump into a bottle before he goes to sleep and he has been eating a lot like 4-5 ounces.

It seems like it could be gas? But I’m not sure. Does anyone else experience this and what do I do about it?