I had that too, if it's on or near your pubic mound it's most likely an ingrown hair. To take care of it at home as gross as it sounds, get a hand held mirror, some toilet paper, and a sterilized needle and looking at it through the mirror poke a hole in the bump (its not as painful as it sounds) and squeeze it like a zit until you see blood not puss, clean it up and your good to go. It might hurt for half an hour or so until it scabs up but it's alot better than the constant pain you'd get leaving it.
I put a warm washcloth on me last night before I fell asleep. It's not hurting anymore. Thank you!
It can have a lot of causes including an ingrown hair, boil or enlarged lymph node. It's best to see your OBGyn to be sure.
Hope you feel better.