When did you conceive if your due date is jan 27 2012?

To calculate the date of conception, we can subtract 280 days (the average length of a pregnancy) from the due date. Counting back from January 27, 2012, we get:

January 27, 2012 - 280 days = April 25, 2011

Therefore, the approximate date of conception would be around April 25, 2011.