i have a dark spot on my penis ..it's been there almost 3 weeks, it's showed up after next day when I made sex (it was hard sex with a lot pushing) and i used a condom. There is no pain, it's flat and it has not gotten bigger. It is just very unsightly. it almost looks ilke a collection of blood vessels underneath that is concentrated in one spot somehow. Like a bruise..but it doesn't hurt. What is it?