It's possible you could be doing too many at one time, or you're not doing them properly. Check with your doctor or continence nurse. They will be able to give you the best information.
You are working muscles & associated tissues that are still recovering from the surgery, so some pain/discomfort would be natural. I would speak to your urologist or Pelvic Floor PT to see if the level of your discomfort is normal. Good luck with it!
