Hello. Sorry about the bump. Try not to worry though. Little things can pop up and usually are nothing. Are you sexually active? It's important to keep your hands OFF of it. Do not try to pick at it or anything like that because that can cause it to get infected. Leave it alone and see if it goes away. It probably will in a couple of weeks if left alone If it changes, gets sore, hurts, hot to the touch, then you have to just go ahead and bite the bullet and tell your mom to get it looked at it. But my guess is it will disappear if left alone.
Come back and tell us if it changes or if it goes away, okay? good luck