Hi, i have pain in testicles and the tube behind them and in lower stomach, but the pain is not severe and only happens when the testicles move ?

Orchialgia: Orchialgia or testicle pain has many causes including infection, trauma (injury) & ischemia (loss of blood flow). Check out http://www.mayoclinic.org/symptoms/testicle-pain/basics/definition/sym-20050942 for starters. Then ask your parents or guardian to take you to see your Family Doc who may refer you to a Urologist if s/he is suspicious for torsion. Don't wait to see if pain will go away.