i am asking my self this question myself...i was religiously charting my cycle cause of the difference between dates i was given last time, literally a week between them, not a problem till they think your 10 days over and you think your only 5 days over!
So i wanted to get it right this time! The first day of my last period was 25th May and i oed on the 8th/9th/10th June. so by my calculations due on the 22nd feb. but my doc says im due on the 28th and the EDD calculator says the 2nd march.....confused much!!! im sure the scan will tell me a different date!
id go with the one that puts your edd at the last possible date....