What Causes Red Bump On The Penile Head?

Hello, I was recently put on antibiotics for a UTI. That seems to have been solved. Yesterday, I noticed a tiny red bump on the head of my penis. There was also one on the shaft. I have had unprotected sex with a female, but she has not been sexually active outside of myself and has no symptoms of any STDs. What could the tiny red spots be from? Thanks.