Actually, there're many conditions may cause testicle pain.
Injury Infection or inflammation
Testicular torsion -- most common in young men between 10 and 20 years old Possible infections include: Epididymitis -- inflammation of the ducts through which sperm leaves the testicle.
Orchitis -- inflammation of one or both testicles, which may be caused by bacteria or a virus like mumps.
Fluid in the testicles often causes painless swelling, but may cause mild discomfort. There are several main types of fluid collection: Varicocele -- enlarged veins in the scrotum that carry blood away from the testicles.
Spermatocele -- fluid in the epididymis that forms a cyst and often contains dead sperm cells.
Hydrocele -- fluid in the area inside the scrotum, surrounding the testicle; common in newborns. Pain may also be caused by a hernia or an unrelieved erection. Well, maybe you could check “99eyao" I know this website provides online service for free, you may consult the online doctors for an alternative opinion. Hope it helps!