If this happened to me, I'd take a que-tip (sp) and see as centered as I could get it, if I could tell where the blood source was coming from. Meaning, from the side (vessles) or further up around the bridge of the nose.
Have you ever had nose bleeds like that before, heavy? It could be somehting unrelated or possibly something where, once you got the piercing it may have cut into a normal flow of some other vessle which in turn ruptured. If it's something simple like that, it should clear up, but it couldn't hurt just to phone the on-call nurse at your doctor's to see if you should come in.
Right now my husband has terrible allergies and certain times of the year cause him to have nose bleeds.