Ususally it's a 2 week check-up, 2 month, 4 month, 6 month, 9 month, 1 year, 18 mo, 2 yr., then once per year after that until Kindergarten. That is just for well-child visits/shots and not every one of those appts. they get shots at.
Your Dr. should be telling you when your next appt. is before you leave the office.