My son is almost a month old and recently started on formula because of difficulties keeping up with breastfeeding/pumping. He started off fine with the Similac, but recently, he's taken to throwing up when my boyfriend(his dad) feeds him. He doesn't throw up at all when I feed him, but occasionally he'll hiccup after a burp and spit up a tiny bit of formula. Like, a very small amount. My boyfriend is adamant that our son is either allergic to the formula or he needs a different type/brand. I told him it's probably because of the way he holds the baby, even though he does try to keep our son propped up while feeding him. Sometimes he'll zone out a little and let the baby sort of slouch while feeding. I think that's the problem, but I'm not really sure. I can't call the pediatrician until Monday, and I'm sort of stressed out/at my wit's end. I just don't know what to do. Has anyone else had this issue? Could it just be the way my boyfriend holds/burps the baby? Could it possibly be the formula? Or could it maybe be acid reflux? My boyfriend suffers from acid reflux, and I have noticed on occasion that our son gets this hiccup-y, watery sound when he's trying to burp, and even after he burps. Sometimes it'll cause him to spit up a little when I feed him, but other times he's fine with no spit up. I could use some advice please.