The purpose of this research study is to determine if taking a birth control pill effects how
well an emergency contraceptive pill called Ulipristal acetate (UPA) works. This type of
emergency contraceptive is the most effective oral method available. However, this medication
is an anti-progestin and most regular forms of birth control contain progestin (a female
hormone). It is unknown if taking the two close together may make the emergency contraceptive
not work well. The overall goal of this research is to improve the effectiveness of
contraception for women and to better counsel women.