MrBennett,
The peripheral nerves which innervate the genitals, actually come from the sacral nerve roots. The bulging discs which you are speaking of are at a higher location, within the lumbar region of the spine.
Testicular pain can actually be referred pain for elsewhere in the body. One of the more common causes of testicular pain is kidney stones or an infection within the urinary tract. Also, it is not uncommon for the back muscles to spasm in cases of kidney stones.
But, the only way to know for sure what is going on is to have an evaluation. You might want to see your urologist for an examination and some lab tests.
Good luck.