To evaluate the impact of a 91-day extended regimen combined oral contraceptive ( 150 g levonorgestrel [ LNG ] / 30 g ethinylestradiol [ EE ] for 84 days , followed by 10 g EE for seven days [ Treatment 1 ] ) compared with two traditional 21/7 regimens ( 21 days 150 g LNG/30 g EE [ Treatment 2 ] or 150 g desogestrel [ DSG ] / 30 g EE [ Treatment 3 ] , both with seven days ' hormone free ) , on several coagulation factors and thrombin formation markers .