Ovulation question!

I had positive OPKs on cd 13&14 this month and currently on cd 19. Yesterday I had mild period-like cramps. If I didn't know better, I would have thought AF was going to rear her ugly head any minute! I asked elsewhere and someone asked me whether it could be ovulation cramps...Is that possible even tho I got postives 4 days prior and negatives since? What else could it mean?