Rash decision

So I found out yesterday that I have Lyme disease. Claire found a tick on me three weeks ago, after I'd been rooting around in the woods looking for red wolf pups (long story). Anyway, last week the tick bite suddenly had a little rash around it. The rash grew angry, and now it looks sort of like this:


I know! I'm a freak (that's not my actual armpit, in case you were wondering). Anyway, so yesterday I went to the doctor and showed her my "classic Lyme disease bulls-eye" rash, and told her that I had done a little investigation on WebMD and that I thought I had Lyme disease. I think she was annoyed at this. How could I possibly diagnose myself? I have no formal training! What the hell do we need doctors for if the patients are going to diagnose themselves? Who am I to question her 10 years of medical school? Anyway, she agreed that I probably had Lyme disease and she gave me a prescription for antibiotics.