im 14 and yesterday i felt a lump joined to my testacle. the lump was not actually joined to the testacle, the lump itself wasn't actually on the testacle, but it was joined to it by something.
I discovered mine at about the same age. It floats around on the left tesatcle, but is attached to something to where I can't get seperation. I have never found out what it is, but it is still there and I am now 28.