Hello, I am 21 male. Around 6/7 years ago I noticed that I have what appears to be something like a third testicle. I never really paid much attention to it as it never caused any discomfort or pain ( and it still doesn't) . However as I am getting older I just wanted to make sure this is nothing to worry about. 

The ball has always stayed a consistent size matching the size of my testicles and has always been on the right side of the scrotum. As mentioned I first noticed 7 years ago but that was because I never felt down there before that time, however I have always noticed (even before) that the right side of the scrotum has always been bigger. 

I have tried to feel it and it does feel exactly like a testicle.

I have read online about symptoms of testicular cancer and I am unsure of what is meant by a "lump" would a lump be on my actual testicle (which I don't have) or will it be like I have described.

Any advice is appreciated

Thank you