The best thing would be to tell your mother that you are having problems so that you can get a good check up from a Gynecologist. There is also planned parenthood that may help you with a check up. Even though you are not pregnant they also help teens with GYN problems. If you don't work they will give you an exam for free.
This does not sound normal, so you definatly want to get a check up for this. Don't put it off, as it could be something that requires medical attention. As far as natural cures go, you still need a Doctor to find out what the problem is.