PLEASE READ!!!!

I've recently been checking my testicles since my friend had one removed about 3 weeks ago and he was diagnosed with testicular cancer! I feel an enlargement at the back of my testicle...if i was to stand up and let them hang i would be feeling the part facing behind me...i dont kno wether i'm feeling tubes or a lump...there's no pain and i only noticed it since i went looking after hearing about my friend! COuld anybody tell me if its a lump or am i just bein paranoid about the tubes? and can yor tubes be bigger on the left testicle than the right?? please let me know!!!