Iv been having sharp pains behind my balls for six months now, my urologist says I don't have a hernia. So I have no idea what it is. Please help me.?

Consider Prostate. The area you allude to could be pain from the prostate. There could be an infection or it may have to do with spasm. You may have an ano-rectal condition that causes spasm and is referred to your area of concern. Maybe you need to revisit, get another exam, more testing or seek another opinion. If not resolved, perhaps seek the opinion of a colorectal surgeon.
Complex . Your pain doesn't sound like it pints to a specific diagnosis. It is likely musculoskeletal, but could be related to your GI tract. You may want to consider colonoscopy or a visit to a colorectal surgeon.