What kind of bump?

I had a bump on my Labia majora for about 2 months. At first it was hard ball, raised above skin and about the side of a pea, I asked my doctor she said it was an ingrown I just have never known of them to stay around this long. It was like a reddish/purple color. Then, the feeling changed, it felt more like a blister. It has always hurt, anytime I ever squeezed it, nothing came out. I took my pants off today and there was puss/blood coming out of it. Was it just a pimple? Do pimples last that long? I’m just trying to figure out what it is so I know what to do if it ever happens again