As an owner of two pitbulls, it breaks my heart to hear more stories about terrible dog owners. I'm assuming you don't know who the owners were? Anyway, first thing is first...if the bite broke the skin and you don't know anything about the owners or if the dogs are up to date on their shots, then yes...you really need to call your doctor. If you know the owner and the dogs are up to date, then you're probably fine.
Next, I'm sure there's some kind of no-kill shelter or agency near you that should be notified. That way the dogs at least have a chance to be put in an appropriate place and not just put down because of an "owner's" irresponsibility.