Hi, a couple of weeks ago after masterbaiting I felt a painless bump on the underside of my shaft, closer to the base, that wasn't there fifteen minutes before. Upon inspection I saw the bump which was maybe about the width of a pea. The bump also appeared to be under my skin, not on the outside like a sore. Also the vertical area around the bump was bruised black and blue. It looked like the bruising ran up and down where the urethra would be. After the initial panic and googling of symptoms I decided to sleep it off and see how it was in the morning. The next day the bruising was essentially gone, but the bump was still there. It has been about three weeks and the bump is still there, but it has shrunk a bit. Any ideas on what it can be? I don't think it is and STD, but in case it helps I had sex two weeks before and used protection.