Here are some ideas that might be the cause of your pain:
Ovulation- This can in fact be JUST as painful as menstration.
Endometriosis (Endo)- can ONLY be Dx through laparoscopy, which is surgery in which they insert a camera into your abdominal cavity. Endometriosis is a condition where tissue similar to the lining of the uterus (the endometrial stroma and glands, which should only be located inside the uterus) is found elsewhere in the body. It causes pain during ovualation and extreem pain during mestration. It is also know to cause heavier periods. Here is a link to info on Endo: http://www.endometriosis.org/endometriosis.html
Of course there is the possiblity that you are having pains near the ovaries, but not at them.
Here is a link to "Cause of Pelvic Pain" http://womenshealth.about.com/cs/pelvicpain/a/pelvicpainp...