My son is 13 years old and has been running a fever of around 101.5 for 3 days. He had stabbing pains at the top of his head whenever he moves. He has loss of appetite and sleeps most of the time. He also has tenderness and minor swelling in his testicles. I took him to the doctor and his urine screen came up negative. The doctor said he didn't know what was causing this, but prescribed him antibiotics and tylenol with codeine for headache. I am very worried, but the doctor said I shouldn't worry as long as his fever doesn't go up higher, and that I should return in a few days if my son isn't any better. Does anyone have any idea what these symptoms could be caused by? Any input would be appreciated greatly.