I Have A Non Painful, Non Bleeding, Small, Smooth, Bump

I have a non painful, non bleeding, small, smooth, bump slightly inside anus. No itching or anything painful. Hurts about as much as pimple and about same size. (I embarrassingly asked my fiance and tgey said it was smooth n slightly pink) I have been screened for stds recently and came back negative. I do have 2 hemorrhoids that I know of. I'm only 22 and I'm kinda scared and embarrased. Also female.