Hey bro, the exact thing happened to me to the "t". A big knot, hurt and was warm to the touch. It did turn out to be a boil/abcess. The only fix for that is to go in and have it "lanced" They'll let it drain, pack it with gauze and its over. I told the doctor it was from a bug bite and he didnt know the difference. Its not like when they cut it open there's going to be a pool of test or whatever and he's going to be like "ahaa, just what I expected, testosterone Enanthate" People get bopils from bug bites all the time.