Do ovaries enlarge prior to period?

Possibly. Ovaries can enlarge at mid- cycle when there is ovulation as an ovulatory cyst can form that may not subside until after the period. If you are worried your doctor can do an ultrasound, as that is what I do on any of my patients who complain of ovarian or pelvic pain to r/o a cyst ( there are many differnet types of cysts) or fibroids or other causes.