Hi twr1959,
Do not feel silly at all. Urinary incontinence- in many forms - is actually quite common in female athletes, especially long-distance runners. I wouldn't let this issue keep you from beginning a running program, but you may want to let your doctor know just for peace of mind. One thing he/she may suggest is Kegal exercises ( to strengthen the muscles of the pelvic floor) for greater control.
Congratulations on your success with the program so far, that is such an accomplishment.
Keep me posted on what the doctor says.
Good Luck,
Paul