Little bumps all over body

Does anyone else’s baby have a rash like all over there body. It’s been on him for like a week and he’s been on a hypoallergenic formula for 2 weeks now so I don’t think it’s that because this just started. It first was on his face so I thought it was just acne and then I noticed it on his legs and then his arms and now his stomach and back. Is this heat bumps or what???