Unintended pregnancy rates in the United States are among the highest of developed nations. These high rates can largely be attributed to incorrect or under contraception of women. One focus of decreasing unintended pregnancy and abortion rates has centered on expanding access to and use of long acting reversible contraceptive (LARC) methods which include intrauterine devices (IUDs), and subdermal implants. Emergency contraception (EC), or post-coital contraception, offers significant reductions in the chance of pregnancy following an act of unprotected or under-protected vaginal intercourse. Oral emergency contraception is commonly used in the United States is the oral Ulipristal acetate (Ella) regimen which reduces pregnancy risk by 89-95%. More effective, but rarely used, is the Cu T-380 intrauterine device. The intrauterine device has the added benefit of providing extended contraceptive use beyond the single episode of unprotected intercourse. The Cu-T380 has been associated with heavier and more crampy menses however, likely dissuading women from use. Among all IUD users, the levonorgestrel IUS has gained popularity over the Cu-T380, perhaps because it offers the potential to improve menstrual related symptoms. There is no data however on the efficacy of the levonorgestrel IUS as a form of emergency contraception. The purpose of this study is to evaluate the efficacy of the LNG-IUS (levonorgestrel- intrauterine system) as a method of emergency contraception. Participants will be randomized to receive either the most common method, oral levonorgestrel, or the LNG-IUS. Participants will then be called 5-6 weeks following method allocation for results of a self-administered urine pregnancy test. Lastly, participants will be asked to complete telephone surveys 6 and 12 months following method allocation assessing their use of a consistent contraceptive method, their satisfaction with their contraceptive method, any use of emergency contraception since their enrollment in the study, and lastly any unintended pregnancies experienced since enrollment in the study. If we could show that the levonorgestrel IUS (intrauterine system) is as effective as the most commonly prescribed method of emergency contraception, we would be introducing another opportunity for LARC initiation and subsequently impacting unintended pregnancy and abortion rates.