I had a small bump "below the belt" which turned out to be a zit. I shower every day and clean thoroughly, so this isn't a hygenic problem. It was obviously uncomfortable to deal with and this was my first, how can I prevent getting another?
Keeping yourself clean is obviously the right thing to do. I assume you are young and zits just happen, especially during puberty. Pores get plugged and infected. There's really nothing more you can doto prevent them.
Those are painful and annoying. That has happened to me too. I just put pop it and put one of those clear waterproof Band-Aids in it for a few days until it clears up. The Band-Aid helps protect if for the continued rubbing from my pants
Wear cotton underwear (synthetics don't breathe and lead to all kinds of issues liek this as well as yeast infections etc)
Make sure you're not using those body wash products there because they mess with your pH balance and can clog pores.