Get help -i had the same kind of problem recently. Only one of mine hurt, and it turned out it was only an infection, which is treatable. But, if just one hurts, it's possible you have a problem-sometimes, the testicle, for no reason, decides to turn around. When it does, it cuts off the blood flow, and basically commits suicide. If it survives or not depends on how long until it's treated. Or it could be a hernia. I'd get it checked out.