The key is the pain. If the pain most often happens at night and at a different time than the popping, that could be so-called, "growing pains." They most often occur in young people about your age and most often in the legs at night. If that's what you're experiencing, they will gradually go away as you get older. Try putting a heat pad on them in the meantime.
It is also normal for your joints to pop but normal popping seldom causes pain. If the pain starts when and where you pop and lingers in that location, you should see a doctor.