Clotting parameters to be measured are those monitored in our previous study of a desogestrel (D) vs. levonorgestrel (L) contraceptive comparison at nearly equal estrogen exposures over 9 months. In this study, PT and PTT increased equally from a pre-treatment baseline, factor V decreased on (D) and increased on (L), and free protein S decreased on (D) and did not change with (L). The impression from this study was that the changes were internally compensating. PAI-1, an inhibitor of plasminogen activation, will also be measured. These will be measured at 1, 7, 21 and 28 days of the investigative month.