two days ago I noticed my left testicle and the underside of my penis were bright red (mostly the testicle, but my penis is slightly red on the underside). I noticed this after going for a run in the hot sun; i'm not sure if that has anything to do with it or not. A day later (today) I am noticing that the testicle is slightly tender, and I think it is a little swollen. I have very vague pains in the left side of my lower abs and lower back also. Any help????