It is quite normal for newborns to bring up milk after feeding regularly.
Is your baby settled after throwing up? Is it a spill or vomit (where everything comes up). If baby cries due to discomfort after throwing up milk, plus not putting on weight, you could see the dr about it. If they are drinking milk well, spill or throw up after but are generally settled, they are fine. Search up the symptoms of reflux.
My girl was a very chucky baby, spilling milk after every feed (bf), sometimes throwing up whole feeds, but she was fine and still piling on weight so our nurse said its not reflux, just likes to drink a lot and their oesophagus is not fully developed yet. In time it did get better