Angry red welt on upper leg where thigh meets the buttocks?

When getting out of the shower the other night, as I was drying off, I felt this bump on my upper thigh where it meets the butt. When I looked at it in the mirror, it appears to be a red welt. Really looking at it, I see that there is a little white spot in the middle of this welt that kinda looks like a little pimple. I can feel another little bump, but can't see it. It doesn't itch, but it is uncomfortable. The welt looks, as my other likes to say, very angry. Any ideas on what it could be? Did I get bit by something?