I Have A Lump On Or I Should Say Near

I have a lump on or I should say near the top of my right testicle, because the lump feels like it can moved around a little bit. It feels like it is located on the epididymis. There is soft tissue around a hard lump about the size of a b.b., So my question would be. How worried should I be? Would this be a cyst or cancer?