ultrasound accuracy on conception date

[michelle1225]

okayy.. i had an ultrasound done when i was 9wks 6days pregnant and the doctor gave me a conception date of april 3rd.. and then i had another ultrasound done at 21wks 6days and the doctor gave me a conception date of april 4th.. well i was with guy #1 on march 26th and guy #2 on april 4th.. how accurate are these ultrasounds on conception dates and is there a chance of it bein guy #1's?

[michelle1225]

well im not really with either of them at the time bc of all the confusion with whose it is but i really wld like to be with guy #2 and for it to be his bc he is jus so much better to me and he wld be so much better with the baby .... so ...

[scareycj]

are you with guy #1 or #2?

I'm doing this myself and quite happy about it!  

[michelle1225]

okayy thank you all .. i was really hopin there wasnt gonna be much of a chance of it bein guy #1 but looks like there is still a chance .. my doc said i was right on schedule for the babies size and weight for me bein as far along as i am both times i had the u/s and they was several weeks apart .. and i never told them my LMP cause i wasnt too sure of it so they had to come up with my due date and conception date jus from the size of the baby on my first u/s at 9wks 6days ..
but thanks for all the help so far ..

[scareycj]

Hey I'm in the same situation as you!

I had an ultrasound at 6 w 5d and my due date is Dec. 1, but i've had other ultrasounds that say my due date is Nov. 25 (which would be from my LMP)

my doctor told me that earlier ultrasounds are more accurate

My doctor says i conceived March 10.  I was with D on that date *protected*.  On Feb 21 i had sex with S *unprotected*  go figure!

[jakesgal88]

I believe the doctors have told me that the u/s can be up to a week wrong in either direction so with the dates of guys being within a week it could really be a toss up. Definitely will need the DNA testing when baby is born.

[KM604]

U/S's can have different measurements at all different stages of pregnancy.  One u/s measured my baby a few days ahead and later in my pregnancy the baby measured 3-4 weeks ahead!  She just measured big for her size, my due date never changed.  If you had regular cycles, I would figure when your ovulation time was (usually 12-14 days before your period) and try to figure it out from there.  Like Mary said, the only way to tell if through a DNA test though.

[MaryAK]

The only accurate way to determine who the father is is through a DNA test.