a doctor would be able to estimate when you concieved by workout out your due date.

have you seen your doctor yet?
has he or she not told you when your due?
if they did they also would have told you when you most likely concieved around.

Hi yes i am due on the 28th August 2009 so does this help, the never told me when i conceived

on the chart where they estimate a due date it should have had an estimated date of conception.
why not call the doctor back and ask when you concieved?