 Women enrolled in this study will be randomized to receive either the LNG IUD or the copper IUD. They will complete a one month bleeding diary prior to insertion of the IUD and again for one month while the IUD is in place. They will undergo phlebotomy blood draw at baseline prior to insertion of the IUD, two and four months. Stored samples will be used to measure D-dimer, C-reactive protein CRP, antithrombin AT, factor VIIIc, activated partial thromboplastin time aPTT and activated partial thromboplastin time plus activated protein C aPTT APC. Both groups will undergo a GYN exam with screening for bacterial vaginosis and gonorrheachlamydia cultures prior to insertion of the IUD. A brief survey to assess the womens experience with the IUD, including symptomatology and satisfaction with the device, will be conducted at the four months after insertion. 