Right testicle lump

It is normal for epididymis to seem bigger towards the top of the testicle, since there is located its part known as caput or head of the epididymis.
Symptoms of testicular cancer are painless lump in testicle, lower abdominal pain, scrotal heaviness, and scrotal swelling or enlargement.
Young age is a risk factor for testicular cancer, but, generally, it is a rare type of cancer.
Testicles develop and change their size at the beginning of the puberty, so, changes in your testicles size and shape depends when you have started your puberty.
In boys, puberty, usually starts at 12 (or as early as 9 years old), and is complete till 16.
The first phase of puberty are penis and testicle development, followed by other characteristics achieved during following years.

If you are really worried, see urologist for check up!
Don't forget regular self examinations of testicles!

Well i am a lot less worried
Thank you very much for replying