They usually heal by themselves. Treatment is no more than a gentle circumferential wrap.
It's probably a good idea to go and get an x-ray.
I've broken several over the years and, in my case, they took a long time to heal.
Oh, and make sure whoever you see knows how to diagnose a broken rib as opposed to a bruised one.
When this used to happen to me in kung fu sparring (I was too old when I started and too slow, so I got my ribs smashed a couple of times) I went to a chripractor who just put my ribs back where they're supposed to be and I was fine. You have to find a chiropractor who does this kind of thing, rather than the traditional chiro that just adjusts the spine. You should also talk to a doctor or medic or physical therapist or nurse or athletic trainer who knows about the application if ice and use of of anti-inflammatories.
could be a bad bruise or you broke a rib or two go to your doctor