I went to use the bathroom and I always check myself and I noticed a bump on the lower shaft of my penis. I don't know if it's the hair or what. I haven't had sex in a few months so I don't believe it to be an STD. Just came out of nowhere. And I don't feel it at all unless I touch it. I always practice safe sex, but I've never heard of an STD that just shows up months later. If I could get any feedback it would be appreciated.

There are many STDs that show up many months after sex. That being said what does the bump look like? Does it look like a ingrown hair or pimple? How long has it been there? Could be nothing, but it might be something you will want to go get checked out.