Hello,
this morning after waking up i noticed a dark spot on the shaft of my penis. It is around 4mm in diameter, painless, no itching and not like a lump. It is visible, but i cannot feel any lumps or that it is raised. I also have no pain when going to the toilet. Im not sure about pain while masturbating, since i dont dare to do that right now. I had sex recently, but with a condom and she did not perform oral sex on me. Yesterday we did some stronger body rubbing with each other, no sex was involved. Could it be a bruise or some popped blood vessel? Or some STD?