A 25-year-old woman complains of pelvic pain during menstruation for the past two years. She has also experienced heavy periods and dyspareunia for the past six months. Her medical, surgical, and gynecological histories are otherwise unremarkable. She is not on any prescription medications. She used to be on the combined oral contraceptive pill, but stopped taking it six months ago, as she wished to become pregnant. Her family history is unremarkable. She only drinks socially and does not smoke.