Puppy's tummy is alittle big... Help?

Hi my pup is a male mini schnauzer, about three month old. His belly is a bit big, scared it's bloat. He has been acting normal, sleeping a bit at my feet under table and attempting to chew plant etc. He hasn't pooped in about five and a half hours roughly but has been letting off gas... I can smell it... Im not really sure if it's been dramatic... I don't think it has... But he is quite eager to eat but has been a bit calmer in terms of not scoffing anymore but does get it down quickly.... We feed him eukanuba... Super premium. We re gonna prob be anyway taking him to vet tomorrow but just waiting for his pet passport so we know if he will need another vaccination now... So what do you think... It's night aswell.... So do you think he'll be ok... Or is it probably worms.... Or does he just need to poop or something??? I hope it's not bloat!!!! Well anyway thanks!!!