I have gotten ingrown hairs on my penis in the past and just let them be. Recently I noticed a large pea sized bump on my penis and am worried if it is herpes or not. I have had the same girlfriend for the better part of two years and haven't had sex with anybody and she hasn't either. I went to the doctor and he said he wasn't sure what it was and could be an std but I'm confused how I would have contracted that. I did some research online and think it is a sebaceous cyst, but I'm still concerned it might be something else. It grew to the size of a pea and didn't really hurt or itch but started to be pretty sensitive when it got larger. It ruptured or popped last night by itself when I looked at it before bed and it was just a little blood. I am going in to get it checked out again in a couple of days but am worried it could be something. Any advice would be great thanks!!