Hi Harrison123. Welcome to the forum.

I am not a doctor.  However, I am a bloke and I a little bit of knowledge. 

Most lumps on the testicles are harmless. There is also a structure at the top of each testicle called the "epididymis" which might be felt as a small lump. It's possible that this is what you've found.  However, Sweetpea1980 has given you some very wise advice: see you GP to discuss the lump.  It's probably nothing, but better to be safe than sorry, and your GP might be able to give you some more helpful information about how to check your testicles and what to look out for.

i know this is almost 2 years on but i recently started checking my balls for lumps etc,

Ive felt a sensitive lump at the top of my right testicle but not on my left. I've been to doctors and they've said it's most likely just your epididymis as it's sensitive and not painful but i can't feel it on my left side.

Can the epididymis be different sizes? 

Thanks :)

I'm not a doctor but bearing in mind the poem about the old man from Devizes  :happy:, I think it's quite possible for these parts of the male anatomy to be different sizes.

I'm not a doctor but bearing in mind the poem about the old man from Devizes  :happy:, I think it's quite possible for these parts of the male anatomy to be different sizes.