Anal skin tags?

Patient: Hi, so uh, I had anal sex with my ex once before we broke up, and both of us were virgins. He didn’t have any STD’s and neither did I, but a few weeks ago I began to notice a small bump, kind of like a skin tag, on the opening of my anus. Over this course of time, it has grown painful and occasionally it will bleed, I try not to think to much into it, but I’m paranoid and think it could be an STD, or something bad. Please help? (Ps, I tried to take a picture, but its difficult to do, sorry I couldn’t be of more help ­čÖü )