imp question regarding ultrasound

[laiba_adi]

I am very confuse n need to ask that y the ultrasound weeks are different from doctor's week.for example I m now 32 weeks.according to doctor and according to this application,but two weeks behind in ultrasound,i.e. 30 weeks.why is it that so? Sonologist has.given me a due date of 15 jan and doctor has given 6th Jan?can anybody answer me as I m very confuse.

[experienced_33]

Ultrasound gives you a due date based on the measurement of the baby. Your Dr gives you a due date based on your last period. You could either be off on the date you conceived or your baby is measuring small.

[laiba_adi]

Thanks a lot,but the sonologist too ask my last date of menstrual period and she says that the baby is accurate according to gestational age.

[sundaughter83]

The first two weeks of your pregnancy occur prior to fertilization. Its counted from the beginning of the menstral cycle. The sonogram is pry counting from conception and implantation so its possible to be different by 2 weeks

[ash2414]

The crown rump length is most accurate before your teeth week. I'm a sonographer. My due date was changed based upon crl. Your doc will probably change your due date