Alright so heres the schpeel. I havent quite gone to the doctor yet because of a few reasons but.. My girlfriend and I were having sex the other night and at first my penis was alright, but 30 minutes later we are done and i had what looks like several blood blisters on the head of my penis. the past 5 days the blood underneath looks to be dissipating and is looking a lot better.. but what caused this? this a symptom of an std or possibly caused some trauma to senor penor?help!