What Causes Testicular Pain After Having Sex?

Hello Doctor. This past week my girlfriend and I had aggressive sex. Last night my right testicle began hurting pretty bad. So this morning I gently masturbated to see if it would relieve the pressure and it did. My semen was thin, almost water-like, and I had a lot more semen eject than usual. About an hour later the pain returned. I have no swelling. There is no difference in appearance when comparing my testicles. Is this something that I should go to the hospital for, or should I avoid sex of any kind and hope it goes away? Thank you.