I have recently started doing pull-ups on a bar. For the past three days, a pain has started in my left testicle. There is no swelling and no pain when touched, but the pain is I think on the back of left testicle. Many times, the left lower back and left testicle pain start together. I am not sure if it due to pull-ups or something else. Please advice me some home remedy or if it's a serious thing.