Go see your gynocologist right away. It might seem embarresing but if you don't get it out there will be serious problems. I had to get a cap removed once, and I know how scary it is. Ask to go to the hospital, and if your parents ask why say you might have a vaginal infection. It is embarresing but in the end you can just laugh it off.
First of all you dont have to worry too much about that. You are sure about not had any sex with any one. It could be some kind of infection. You have to see a Gynocolgist as early as possible and examine your vagina. Because it is very sensitive parts and always have contact with urine, therefore easy to increase the infection. Each time after toilet clean with antiseptic lotion. Please take care, All the best and Very good health. Happy life !! jobsyn@gmail.com