Could perhaps be reflux which is common among newborns under 3 months. My boy also spit up sometimes aft feed. As long it's not projectile vomit, don't worry too much. Hold baby on an incline when feeding him and burp him as much as you can. Massage baby's tummy often so that he can let the air out. If baby is on formula, cld be the milk too. If on breastmilk, don't worry too much, it's quite normal. For my boy, it improved when he had more tummy time. Of coz wait abt an hr aft the feed.
feed half and burp him... let him lie on those inclined bed, go see pd for an anti puke med if it's too sever... my boy puke after almost every feed for almost a month. he outgrew it when he's about 3 mths plus
He is 1 month plus currently