Should I see a specialist for 3 hours of testicle pain, or can my regular doctor take care of it?

Don't wait. See a dr. Immediately. Could be testis torsion if pain came on suddenly. If present needs to be fixed asap. Try and twist testicle like opening a book, this could immediately relieve torsion or pain if testicle is twisted. Get urologic help immediately if not relieved. Could be epididymitis, scrotum wouyld feel hot and pain slightltly improved if u gently elevate testis.
Testicular Pain. I would see your regular doctor first to see if he can help and let this doctor decide if you need a specialist.