I'm A Fairly Healthy 37 Year Old Male (I Do

     I'm a fairly healthy 37 year old male (I do smoke cigarettes). Over the last 2 months, I started feeling a sudden pain in my right side testis/lower abdomen/groin ONLY during climax with my partner during intercourse. I've never tested positive for S.T.D.'s. The pain is a Dull Ache that lasts only a few seconds upon climax. I have no other pain throughout the day/night. Why am I "all-of-a-sudden" getting this pain only upon climax/ejaculation? I am scheduling an appointment to see a Urologist in a couple weeks.
     Any thoughts on what my condition MIGHT BE? I'm having NO other symptoms ie (Frequent/Inadequate Urination, Burning Sensation, Frequent Pain)