So I came home from school with a big red bump on the lower shaft of my penis . It wasn't there earlier that morning. And I don't think it's an std because I've never had any sexual intercourse. So I was wondering what it was because I'm a bit worried it could be something bad. It's red with a white dot in the middle there is no pain or irritation and it's located on the lower part of my penis shaft near the testical.