Ive got a hard red lump, about the size of a small pea, on my inner labia near my clitoris. I've had a few before and they generally go away. There is no visible head to it, but it is tender to touch. I've only ever had protected sex & I've been with my current partner for six months, who had an STI test done a few months before we started having sex- it was all clear. Any ideas on what it could be?