Hi there. After having sex with my girlfriend a day later I had 3 scabs apear on the tip of my penis.. ther had been no signs of abnormalitities on my penis before this encounter and I am a little bit worried about it. I have been previously checked for stds and they came back clear. The scabs jst appeared with no prior warning.. my girlfriend was on top at the tjme but she had only pulled her trousers down a little bit and im thinking it could maybe have been friction from her trousers