Even dating scans can be inaccurate for the due date, but they are never as inaccurate as using the menstrual period. For instance a dating scan done at 6 weeks could get the date wrong five days either way.
How accurate are scan dates?
How accurate is the ultrasound examination? The earlier the ultrasound is done, the more accurate it is at estimating the babys due date. Ultrasounds performed during the first 12 weeks of pregnancy are generally within 3 - 5 days of accuracy. The most accurate time is between 8 and 11 weeks gestation.
Can sonographer be wrong about due date?
In any case, ultrasound does not give a very accurate prediction of the actual birth date.
How do you self check your stomach for pregnancy at 3 weeks?
0:262:33Tummy Check - YouTubeYouTube