Would like to find out when i conceived

Patient: My due date is 28th Aug 2015.. Is it possible that I conceived around the 27th of Nov 2014?

Doctor: Hello,If your due date is 28th august 2015 by ultrasound , then by Naegle’s formula your date of conception should be 21 november 2014 or a week beyond that ie 27 nov 2014. There is always a discrepancy of one week in actual date of conception and ultrasonological inference. So the conception should be between 21-28 th november 2014.I hope i have answered your query,wishing you safe pregnancy,regards