This study will examine the combined effects of a continuous oral contraceptive (OC) regimen with supplemental estradiol therapy on headache severity and occurrence in subjects with documented Menstrually Associated Migraines (MAMs). The subjects enrolling in the study will have cyclic menses either due to spontaneous ovulation or use of cyclic hormonal contraception (pill, patch, or ring). Enrolled subjects will start a continuous OC regimen following two baseline menstrual cycles. If breakthrough bleeding/spotting (BTB/BTS) occurs, the subject will institute a 4-day hormone-free interval (HFI). In an attempt to prevent/lessen the severity of headache during the HFI, subjects will be randomized to oral estradiol or placebo during this period. If no BTB/BTS occurs after 80 days of continuous pills, the subject will institute a 4-day HFI during which they will be randomized into estradiol or placebo groups. The purpose of this research study is to examine the effects of continuous oral contraceptive pills and oral estradiol on headaches that occur around the time of your period. Many woman take continuous oral contraceptive pills (OC) and when OCs are stopped they may get headaches. This study will examine if taking estradiol around the time of the period will affect the headache, and how it will be affected. This study is a prospective trial. A subject's participation will last approximately 32 weeks.