From your symptoms of painful periods and spotting in between the periods with ovarian pain, endometriosis and PCOS should be ruled out. Symptoms of endometriosis include pelvic pain(usually before menstruation but sometimes during intercourse,urination or defecation), sometimes diarrhea or constipation,irregular or heavy menstrual bleeding,sometimes blood in the urine and inability to conceive.
I suggest you to get it examined from a gynecologist regarding these two possibilities.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.