Testicular Pain More Condition_symptoms What Could The Cause Be If My Boyfriend Has Testicular Pain?

What could the cause be if my boyfriend has testicular pain? - testicular pain more condition_symptoms

He said he began to hurt right after we had sex 3 days ago. He says he does not hurt that shortly after he had an orgasm, and since then he is always injured. He said that only one of his testicles. He feels pain when walking or moving much. What could be causing this? Do I need to see a doctor? What doctor, if you do not have health insurance?

Any help is welcome. Please matures. Thank you.