After having sex with my boyfriend, I noticed a red spot on the opening of my urethra. He and I have tested negative for all STIs (including herpes) and did not engage in rough intercourse. The spot is painless, no pus is present, and it does not hurt when I pee. I only noticed it after looking with a mirror. The spot only shows after we have sex, goes away a few days later, and then returns the next time we have sex. What could this be?
Please help with any info you may have!