Fussy Preemie

So may sweet baby boy came home from nicu about a week ago, he was 6 weeks early, hit what would have been the 36 week marker this last Sunday. He’s doing great, I pump like crazy and he eats about 65ml a feed, gaining about 2oz a day, he’s finally over 5lbs. The last 3 days though we’ve noticed a lot of noisier sleeps, seemingly uncomfortable, like he’s about to cry sometimes, especially at night. The only thing I can come up with is gas or reflux, any suggestions? He’s a preemie so I’m not sure I can give him anything like gripe water yet, going to call the peds office tomorrow for help but also looking for a temporary fix to help him sleep better.