I have been on BCP since 2001 - I was diagnosed with a Pulmonary Embolism on April 6 - the Dr took me off BCP immediately and started me on .5 Coumadin (blood thinner) daily. I had a period on April 11 (5 days), May 6 (4 days), May 29 (5 days) and the next was June 24 (9 days). I had calculated I would start again around July 21. I have not started and I have taken 2 home pregnancy test (July 23 and July 25) both came back negative. Obviously, Im not pregnant. When calculating start date - I have always counted 28 days from the start date - Is this correct or should I count from the last date? Confused! Please help.