I know I've posted before, but things keep happening and it freaks me out.
I masturbated 3-4 times yesterday (a lot, I know) and at night I noticed one tiny red shiny bump on the shaft of my penis. I did have sex the day before (2x) with a guy who's status I do not know, but he says he has never had any coldsores or genital sores. This bump does itch/sting/tingle and possibly burn. It's so small that most people wouldn't even notice it, and I wouldn't either if I didn't inspect my penis. Does this sound like herpes or heat rash or just a pimple?