What if I re-clot on the anticoagulant?

If taking your medication as prescribed, and you did not miss any doses, the chance that you will re-clot is only 1-2 % at most. If you ever develop a blood clot when you are on anticoagulants, 3 most likely explanations are, 1. You have not been compliant with your medication, 2. You did not take the drug correctly i.e., you did not take with food, or 3. You are taking other medication which interfered with the anticoagulant. A good example of drug interference would be anti-seizure medication.