Pain between anus and testicles that occurs while running.

I have a feeling between my testicles and anus that typically only occurs while exercising. I wouldn't really call it a pain, just a feeling that I know I'm not supposed to have. There is no lump that isn't supposed to be there. I have no problems peeing, no pain, no blood, no discharge, etc... No problems doing number 2, no pain, no bleeding, etc... Any idea what could be causing this pain? It's been here 6 months I'd say? Maybe it's just the hypochondriac in me, but I am trying to figure out if it is worth getting looked at or not. I've looked at symptoms of prostate and anal cancer, and I have no prostate symptoms. The only symptom I have of the anal cancer is the pain type of feeling. Like I said, it typically only occurs after walking a lot or during exercising.