This is why sexual education should be mandatory. As long as you didn't get any semen or seminal fluids in or around her vagina you will be fine. But if you're going to have sex use a damn condom. You should be able to get them from your school nurse. Or you can go to any petrol station. If they say you're too young (they shouldn't) just pull the whole "fine, I'll get the girl pregnant" speech.