Continuous Administration of Oral Contraceptive, Primary Dysmenorrhea

Inclusion Criteria: * Healthy women ages 18-35 with a history of PD (onset \< 3 years after menarche). * Subjects must have had regular (25-31 day) menstrual cycles for the three month period preceding enrollment, with symptoms of moderate to severe PD during those cycles. Exclusion Criteria: * Patients who have contraindications to OCP therapy. * Known or suspected secondary dysmenorrhea (major abdominal or pelvic surgery, endometriosis, pelvic inflammatory disease (PID), ovarian cysts, pathological vaginal secretion, chronic abdominal pain, inflammatory bowel disease, irritable bowel syndrome). * Concomitant treatment with oral contraceptives, GnRH agonists and antagonists, antiandrogens, gonadotropins, anti-obesity drugs. * The use of contraceptive implants, injectable contraceptives or intrauterine devices. The washout period on all these medications will be 3 months. * Migraines, depression requiring hospitalization or associated with suicidal ideation during previous estrogen or ocp use. * Known or suspected hypersensitivity to trial drug. * Patients enrolled simultaneously into other investigative studies that require meds.