Im 15, not that strong and was lifting 3.5 kg dumbells for as long as i could in my right arm, I was alright for the day after but then then todaywhen I woke up, when I outstreched my arm it hurts at the joint. have I just pulled it have I dont something else and also wat should i do, Im also next week on wednesday goin skydiving, if it still hurts should I still do it