Did he injure his self? Do you see any kind of insect bite? You need to get him in to see his Dr tomorrow to find out what's going on. Take care. Remar
this happend 2 me around the same age it was terrible! But don't worry 2much yet it could be 1 of a few things, eather the long tube like thing attached to his nut got tangled cutting off circlation, or it could be a urinal infection or it could be tortion ! the first one i got a couple times from playing sports when i was a kid! if its tortion it could be terrible for him! eather way take him 2 the doctor first thing seriously school can wait! the doc will give him a xray and probly give him a antibiotic! and with in a few days he should be ok just seriously no runing or sports till his nut is back 2normal! tortion is all you have 2 really worry about cause he may need surgry! Hopefully your boy dosen't have tortion! Eather way i know how he feels and i hope for all the best of luck for him!
He may have a torsion... please take him to the doctor.