Bump near my anus.

So I have this very tiny bump near my anus. It’s just one bump that is the size tip of a pen for now and it’s the color of my skin you can’t see it , but you can feel it. A couple of months ago it did grow into a big bump like the size a tip of the number 2 eraser but a little bigger you still couldn’t see it but you have to feel it and it was the color of my skin. When it was big it hurt and it was itching. ( that’s not the first time it has gotten big.)(A couple of years ago when it got big my doctor tested it and I forgot what she said but I know it was nothing too serious because I would have been on meds by now. I went to the gyno for it and she looked at it and she said it’s just an ingrown hair.) She also did test me for std and hiv and all of that came back negative. But I guess when I shave down there I get some of my butt hairs and when we my period is about to come on sometimes that’s when it gets bigger. So I stop shaving my butt hairs for a couple of months so it hasn’t gotten bigger. But it’s still there. But my main issue is it’s been there for years maybe 4 years! I’ve been to the gyno since and did my yearly testing and I didn’t have an STD. But it is still a fear of I might have an STD. I’ve been with my boyfriend for a year and I want to have sex with him and I’m scared to still him about the bump. I’m scared he might get mad like it’s an std or something. To back track I did have unprotected sex 4 years ago and got tested since and everything came back negative.