The ultrasound said I am nine weeks pregnant however I dated it at eight, which is right?

Answer by  sillymomof2 (26)

The ultrasound calculates your date using the baby's measurements. Dating by your lmp can be off by a week or more. In this case, go with the ultrasound.

Answer by  emtrobstu (233)

If you know for sure that you are eight weeks, then I would go with eight weeks. Ultrasounds are accurate within two weeks. Si if an ultrasound says you are 9 weeks, the range is from 7 to 11 weeks. The further you are in the pregnancy the better the ultrasound results will be.

Answer by  Angie83 (180)

The ultrasound date is usually more accurate. The ultrasound estimates the dates by the baby's bone measurements. All of my ultrasound dates for my three children were more accurate.

Answer by  seb (220)

Both are really just an estimate however, the ultrasound should be most accurate based on the rump to crown length of the fetus. There is really no way to know the exact moment of conception. By knowing both pieces of information you should be able to come up with a pretty accurate due date.

Answer by  bash (1026)

The Ultrasound cannot be wrong. However, if your period is regular, your calculation also seems right. There may be some mistake in your calculation. Rely upon the ultrasound scanning.