Emily - first things first, don't worry! It sounds like you have a small infection, and if so this can be treated in complete confidence. These things happen from time to time, and there's every chance that it's not even related to your activities with your boyfriend. Go to your GP, and he/she will prescribe something - you need not mention what you suspect the cause to be. You don't need to take an adult, and once again DON'T WORRY! Doctors have seen everything. You'll be as right as rain in no time.