Women ages 18-50 with Uterine Fibroids and/or Endometriosis can participate in this study to evaluate the safety and efficacy of Elagolix in Combination with Combined Oral Contraceptives. For premenopausal females 18-50 years of age and not pregnant or planning to become pregnant in the near future. Need a documented diagnosis of fibroids and/or endometriosis that can be done as part of the study.