As a result of this, many studies have been performed in attempts to discover therapies for unscheduled bleeding in progestin-only contraceptive users. Some of these studies include those investigating selective progesterone receptor modulators, such as mifepristone and ulipristal acetate (UPA), which did find some benefit. Although a previous study showed mixed benefit, the investigators feel that this medication has demonstrated both biologic plausibility as well as clinically important outcomes. This previous study may not be entirely translatable to the proposed research as therapies were used for different indications (prophylaxis vs. treatment) and different progestins and delivery systems were studied. Therefore, the investigators believe UPA should not be discounted as a potential therapy. UPA may provide an additional safe and effective option for treatment of irregular bleeding with implants in women. In addition, UPA is currently available in outpatient pharmacies in the U.S. as a single 30mg oral tablet.