Our DS1 had reflux and it caused him a lot of distress. It also woke him up and you could hear it coming up his throat. vomit and cue the screaming. DD has a milder form and she doesn't scream so much, but she has to wear bibs all the time. I think you can tell it's reflux as they will vomit whenever, hours after a feed etc and it can be quite chunky/coagulated and smell acidic. I guess if it's not causing your bub any distress, maybe they're just a vomity baby?