Cramping after breastfeeding at two months post partum?

I was wondering if anyone has had the same experience. I am exclusively breast feeding my almost 2 month old son and have had bouts of severe cramping after breastfeeding in the uterus area... I also had a tubal ligation during my c-section and the procedure resulted in a t shaped incision in my uterus because of the way the baby was positioned... was wondering if this is my uterus still shrinking or possible ovulation after a tubal ligation... any ideas as to what it might be would be greatly appreciated!