Can you get incontinence from being hit in the bladder/penis region?

Very unlikely: Urianry incontinence stems from trauma to the groin area usually is from damage to the sphincter that controls urine. Although it is possible, it is unlikely to cause incontinence from just a hit to the groin unless there was severe trauma to this area including a fracture to the pubic bone or pelvic bone.

Yes : If your bladder is near capacity and you are hit in this area suddenly increasing intravesical pressure.