Hi, i'm 16 and not long back went to the doctor for a concern about a free floating lump. After the exam he said that he couldn't find the lump and perhaps what i was feeling was a cyst. I'm just curious to understand what type of cyst this is as it moves all around the scrotum seemingly not attached to anything, which moved easily when touched. He mentioned a epididmal cyst, yet the cyst can move completely to the opposite side of the testicle from the epididymis. This is a small hard cyst and if anyone could help me understand what i'm feeling would be much appreaciated. 

I must mention there is no pain, even when touched.