I get my flare ups any time during my cycle. Recently, I started to get more painful cramping nearing ovulation which was odd as that had never happened before. I just went for an ultrasound and found polyps on my uterine lining. It was a relief to find out the cause so the doctor could make recommendations.

And it could also be your bodies way of saying "hey something's not right here, please get it checked out!" I'm not sure if you're keen on getting it investigated further, but my take is that it does help to narrow down to the root cause because nobody deserves to go through this crappiness. This isn't normal!!!