History of deep vein thrombosis and/or pulmonary embolus within 3 months of study entry Patient with a history of thromboembolic disease to include pulmonary embolus or other extremity deep venous thrombosis Deep vein thrombosis (DVT) or pulmonary embolus which require use of oral anticoagulants or, if on low molecular weight heparin, have not been on a stable dose for at least 2 weeks Patients who have a history of deep vein thrombosis or pulmonary embolus and are stable on anticoagulation for > 1 month are eligible Patients with a recent history of deep vein thrombosis or pulmonary embolus, in the six months prior to enrollment are not eligible for this study Patients with any of the following within 6 months of enrollment: deep vein thrombosis, pulmonary embolus, myocardial infarction, cerebrovascular accident, unexplained loss of consciousness Patients being treated with full dose warfarin are excluded. Patients with history of deep vein thrombosis or pulmonary embolus who are being treated with therapeutic doses of low molecular weight heparin or prophylactic dose anticoagulants may be enrolled. History of pulmonary embolus and/or substantial deep vein thrombosis History of documented pulmonary embolus within 6 months of enrollment Conditions contraindicated to progesterone treatment (including, but not limited to, thrombophlebitis, deep vein thrombosis, pulmonary embolus, clotting or bleeding disorders, heart disease, diabetes, history of stroke, allergy to peanuts, hypersensitive to progesterone and liver dysfunction) Known history of deep vein thrombosis or pulmonary embolus except in patients where the cause was directly related to foreign body implants, i.e. central venous catheters, portacaths, etc. History or clinical evidence of deep venous thrombosis including pulmonary embolus within 6 months of treatment Cerebrovascular accident or pulmonary embolus within 3 months of randomization. Pulmonary embolus or thrombosis of the deep venous system (deep vein thrombosis [DVT]) within 2 weeks of starting study treatment; patients who had a history of thromboembolic disease should be stable on therapeutic anticoagulation using low molecular weight (LMW) heparin for at least 2 weeks prior to the start of study treatment; use of warfarin (or derivatives) is not allowed at the start of study treatment Patients who have had a deep vein thrombosis or pulmonary embolus within the past 6 months are eligible if they are on stable therapeutic anticoagulation Patients with a recent history of deep vein thrombosis (DVT) or pulmonary embolus (PE), in six months prior to enrollment are not eligible for this study Within the past 6 months:\r\n* Acute pulmonary embolus\r\n* Deep vein thrombosis CONTROL (HEALTHY) GROUP: Within the past 6 months:\r\n* Acute pulmonary embolus\r\n* Deep vein thrombosis History of: Thrombophelitis, Deep vein thrombosis, Pulmonary embolus, Clotting disorder, Bleeding disorder, Heart disease, Diabetes, Stroke, Peanut allergy, Liver dysfunction, Hypersensitivity to progesterone