Boy, girl, it doesent matter... Hormones are a bitch, and im 14 and it can be really annoying sometimes, but ive somehow learned to control it... Just focus on something else that has apsolutley nothing to do with sex, and dont touch yourself... You should be fine...
But yep, i can "proudly" say that 14-15 years of life are the worst years when it comes to sexual stuff and hormones. At that age, they are raging. But yeah, its not a bit problem, if youre at school and get horny, just concentrate on the classes ans dont think about anything horny... Works for me... xD