 Women enrolled in this study will undergo phlebotomy blood draw at baseline prior to starting the minipill, one and three months. Stored samples will be used to measure D-dimer, C-reactive protein CRP, antithrombin AT, factor VIII, free and total protein S, fibrinogen, von Willebrand factor vWF and normalized activated protein C sensitivity ratio nAPCsr. Both groups will undergo a general physical and GYN exam prior to enrollment. This exam and the blood testing will be provided free of charge. Patients will not be prescribed the minipill after completion of the study and will be advised to consult with their primary care physician or hematologist if they wish to continue this medication. 