I recently started using an insulin pump a few months ago. Everything has been fine until, today when I changed the infusion set. I pulled out the old set and started rapidly gushing blood from the injection site. The bleeding has stopped, but I now have a small, swollen black ring, about the size of a pencil eraser, around the opening. Has anyone ever had this happen before. Will it go away soon, or leave a scar. Why might this have happened? Is this an infection? My boyfriend's mother is a veteran ER nurse, so I'm going to have her assess the damage. I just want to know if this has happened to others who are willing to share stories about the experience / outcome.