I'm a 17 years old male, and I occasionally feel a sudden burning feeling to my penis and rectal area. It often goes with a sudden need of peeing (for example, I would urinate as if I didn't for hours while I did it some minutes before). The pain generally lasts some minutes and then disappears. For precision: I've never had sex before, so it can't be a STI. As it is very occasional and doesn't last more than 15-30 minutes it doesn't represent a big issue but I'm still worrying about it. Hope anyone can help, thanks from advance.