Due date is 03/13/16 based on last period. due date based on 7 wk us is 03/13/16. 13 wk us due date is 03/16/16. 20 wk us due date is 03/08/16. could this baby have been conceived 12/14? i ask because i had a different partner in 12/14.

No: Average duration of pregnancy is estimated at 280 days or roughly 9-10 months depending upon how you count. Even tho average duration can vary by up to a month or so (http://www.bbc.com/news/health-23594668), odds of getting pregnant in December 2014 and then delivering in March 2016 are slim to none. http://www.perinatology.com/calculators/Due-Date.htm estimates date of conception as June 2015

Ans: No. If you use your due date and the early us are pretty accurate. You could not have conceived in December