It is difficult to say which date you should go by. Generally ultrasound dating is more accurate and earlier the ultrasound more the accuracy. But it really does not matter as the dates are pretty close. Generally I'd go with the EDD unless you're not sure of the LMP, in which case you may need to go with the AUA (average ultrasound age).
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.