Ultrasound (US) has an inherent margin of error for calculating the gestational age. This margin of error is likely less than 8% when the ultrasound is performed between 5.5 weeks and 6.2 weeks, though human error in measuring early pregnancies (such as including the yolk sac in the measurement of the fetal pole) can create significant error.When the EDD based on ultrasound is more than 8% different than the EDD based on the LMP, then the estimated due date based on ultrasound is generally used and considered preferable.A pregnancy test can be positive usually no earlier than 3.2 weeks, if even then.So understanding when the first test was positive (and in some cases when a test before that was negative) can help you establish minimums and maximums that you expect the gestational age to be in early pregnancies.Within 3 minutes your 'Pregnant' or 'Not Pregnant' result in words will appear on the screen.If the result is 'Pregnant' the test will also indicate time since conception occurred ( 1-2, 2-3 or 3 weeks).Important decisions at the end of the pregnancy regarding the timing of delivery of both normal and high-risk pregnancies hinges upon the early establishment of the EDD.
These early symptoms can occur even before the missed period."I have been buying Clearblue for years and I absolutely love their products. The estimated date of delivery (EDD) is incredibly important in providing quality prenatal care.The most common error made in determining the estimated due date is not taking into account the accuracy of the last menstrual cycle or the length of the menstrual cycle.If a woman has a 32 day long cycle, then four days have to be added to adjust the EDD.
The patient may respond that she only had one or two days of spotting and that this was different than her normal periods, and/or that perhaps it came a few days earlier than she had expected.