For women only, can you help me?

It's a little embarring, but I've got a weird bump on one of the lips of my . It doesn't hurt to sit down, or urinate, or any other such thing, it only hurts when I push on it (aka, when I'm wiping that area.) I'm a little nervous about it, but I figure it's just a big ingrown hair follicle (I know, gross), but I am on period and there IS hair down there, so combined with the nastiness of being on your period, as well as the hair, we can ume it could possibly be an ingrown hair. I can't see it very well, but I can feel it and it's a good sized bump. I figure I should just leave it be for now, unless it gets bigger. Do you think that's a good idea? I don't want to waste 200 dollars for an appt. just for them to tell me it's an ingrown hair follicle.