Ovulation

So normally when I ovulate I get a dull cramp on the side I'm ovulating on for a few hours and and it goes away. This morning I had a vaginal ultrasound and I'm ovulating from the left ovary, which I can feel, but instead of it being a dull cramp that goes away soon after, it progressively got more painful throughout the day. Anybody have experience with this? Could it be that I'm releasing more than one egg and that's why I've been cramping all day?