Small lump on my ! HELP!?

I am 12 years old so I don't really know nothing about lumps and bumps around your body? The only thing I can think of is cancer, but I doubt it is, I hope!? Anyway, about half an hour ago I crossed my legs when I was sitting on the sofa and I felt something really sore around my so I pulled down my trousers [I'm home alone untill 11] and I saw something on one of my lips so I looked carefully and it is a small pinky whitish lump, I does not hurt that much when I walk, it is just sore. It might be because of this but I shave my pubic hair with a razor. PLEASE ANSWER! HELP! I AM REALLY WORRIED!