Whats the error of margin for u/s dating at 11w4days on 01/20/14 with edd of 8/08/14 as far as conception date? is 11/25/13 eliminated from conception

Approx +/- 8 days: At 11wk 4d the margin of error is approximately +/- 8 days. The calculated date of conception according to the stats you gave, is 11/15/13. I don't think you should eliminate 11/25/13 as the conception date, although it's unlikely to be this date. Good luck.

You should be: Discussing all of this with your OB since your OB should answer any dating questions you have any any ?S about conception date with that us conception would be 11/15 as your OB could have figured out, us should be acurrate + or - 3-4 days but ask your OB what their range is.