Is it normal to have one much testicle bigger than the other? my right testicle is bigger than my left by quite a bit

Depends on details: Most guys have a right testicle that is about the same size as the left. Occasionally, a boy will have unequally sized testicles as he grows up. If that is the case, and the unequal size has been there for years, and has been checked by a doctor, then that is considered normal for that person. However, if an adult has one that later grows bigger than the other, his doctor will check for a tumor.