My right side of my scrotum is a small bit bigger than the left side my testical has been sore on and off for the last few days what's wrong?

Want urologist: I think you want a urologist to check this. It could be as benign as a bruise or something really important. I would want an expert opinion rather than guessing myself.

Here are some ...: No perfect symmetry in size and level is expected in both sides of a paired organs like the sac and its contents - testicles & epididymides, but their consistency is about the same. Nontheless, such minor discrepancy is not clinically important as long as being functional. As to testicular soreness / pain, that is different issues which require evaluation to rule out inflammation, twisting, or...