I am a 24yr old male and I have discovered a hard lump inside of my scrotom, on the side of the my left testicle. it seems to be attached to my testicle and is tender to the touch. if i am not careful i get a pain like i ve been kicked or punched in the testicles. it has also started to hurt just a bit after i ejaculate. I don't know what it could be but it is starting to hurt a bit more but i do not have any other symptoms of testicular cancer and everything else i find doesn't sound like it. thank you.