Hi thanks for your question. I have both good and bad news for you. First the good news that you had sex three days after your last cycle, which was your safe period and chances of pregnancy are very, very less. Bad news is if you have conceived, abortion is difficult, not for the reason that, you are having venous sinus thrombosis but because you’re on oral anticoagulant, which can cause profuse bleeding during abortion process. Secondly if you want to continue pregnancy chances of congenital abnormalities are high as warfarin is known for congenital abnormalities. Chances that you have conceived are very less, as mentioned above. Period could be delayed due to anxiety (tension).45 days have already passed; this is the time pregnancy test turns positive. Get your pregnancy test done to rule out/confirm pregnancy. If test turns out to be positive, you have stop warfarin 3 to 4 days before planned abortion. Consult a gynecologist who in consultation with you treating physician may decide further course of action. Hope this answers your question.