They're treating a blood clot on my heart with warfarin and aspirin what are the risks of me having a stroke due to the medicine?

Stroke risk low: While you are on blood thinners, your risk of a blood clot causing a stroke should be lower, and these medications can sometimes be used to prevent or treat stroke. Your risk of bleeding is higher, which can also be dangerous. For this reason it is important to have good control of your blood pressure and to avoid activities which put you at risk for head injury.