I Noticed A Red Bump On The Front Of My

I noticed a red bump on the front of my vagina. It's like at the top of the lips, but on the front of my vagina. It's a red bump. I'm not sure how long it's been there; maybe 2-3 weeks. It doesn't bother me at all, and it's only a little sore when I touch it. It doesn't itch and it isn't sore when I don't touch it. It literally doesn't bother me at all. What could this be? I'm really scared it could be something crazy like cancer or something, but at the same time, it could be something as simple as a pimple. I do have a bit of a problem with acne. I have a boyfriend who I am sexually active with. We are both clean, however, we don't use protection. This is the first time this bump has ever shown up. We have been sexually active for over a year. We have not changed any of our habits, so I don't necessarily think the bump is due to sex. Oh, and I'm 18 years old if that matters. Could you please help? Thanks.