Good question, Andy, and one I would ask your doctor who has examined you and knows best where you are on the five stages of puberty. testicles need to be 2 degrees Fahrenheit cooler than body temperature to function well which is why the scrotum or sack exists. they should be firm, smooth and painless unless injured, cold, or a recent emission of sperm and semen took place which can result in a temporary discomfort or "pain". Many boys in puberty develop a swelling of vessels around the testicles--a harmless condition called "varicocele" which can also cause some occasional pain. Get it checked out with your doctor to be on the safe side.
Wayne Yankus, MD, FAAP
expert panelist: pediatrics