Testicle shake?

y my testicle shake somtimes , juz 1 second lidat , no pain , or is it normal? my father and brother say sometimes it will shake as long as its not constant , i am here to ask whether tats normal , n the vibration mostly occurs on the left side. is it normal? urologist has feel my testes , he say it is fine n there is no lump in the testicle , sometimes on top of my testes theres mild pain, tats all. i wan to ask if a testicle with no lumps can have cancer? both side of my testes is not hard n nice , its hard when i take hot bath n it hang low , n soft when i am cold or when i am up . juz wonder if a testicle wif no lump can be cancerous. tell me whether i have.there is good sperm count in me.i am 14 +.testicle does not nid to remove if its noyt cancerous rite. thx , plz answer . i am worried.