Urinary discomfort

I recently went to the dr for testicular pain, and had a sonogram and urinary and blood work done. The sonogram showed a small hydrocele but nothing that would cause the pain so they sent me to a urologist The blood and urine showed nothing. The urologist said the pain was because my left testical hanged on a angle. I had recently just urinated and had gotten a sharp pain in what felt like my uritha. I should also add that once a month or so i get a irritation in my penis (this usually happens after i masturbate). What could this be?