I have started my first dose of norethisterone this evening, however before I took them I felt as if AF was about to arrive.... if miss the doses does anyone know if AF will come naturally still or would the medication have delayed it already? I'm only hesitant to continue if not needed as I've had them previously along with letrozole and I am just evil on them and get really down so would like to avoid making myself feel like this if I don't have to