My recommendation would be to find a pelvic floor physical therapist. Both of the ones I've seen have been extremely knowledgable and understand how to diagnose and treat something like that.

I did not have an issue with prolonged UI after my prostatectomy but did experience some stress incontinence starting a year after my salvage radiotherapy. It only occurs when I get in certain positions and make certain movements, almost always at the gym. The fist episode was when I was doing some chest presses on the bench with dumbells. When I got back up from the horizontal position whatever was in my bladder came out. Fortunately I was wearing some dark colored shorts that day!

I've worn a light pad when I go to the gym since and make sure I empty my bladder when I get there. Very occasionally if I get in similar positions at home and make sudden movements getting up I can get some dripping. The PFPT I'm working with now has me doing a bunch of exercised to strengthen certain muscles thoughout my pelvic floor...not just Kegels. I was astonished to see how weak some of those muscles were when she did functional tests.