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 you see the baby at 5 weeks?

You may see the gestational sac in an ultrasound as early as 4 1/2 to 5 weeks. The gestational sac increases in diameter by 1.13 mm per day and initially measures 2 to 3 mm in diameter, according to the National Center for Biotechnology Information .