I am trying to figure out conception date. I am due April 15th 2008. On August 22nd, my ultrasound said I was 6 wks, and 1 day. Doctor said I would have conceived around the 23rd or 24th of July. I know technically my baby would have been only 4 wks old at the ultrasound. I am uncertain when I had my last period and my periods are erratic. With the US and due date, is there any way I could have conceived before the 23 rd or 24th? How accurate are US? Doctor told me the earlier the US the more accurate it will be.