Join the Meeting Place for Moms!
Talk to other moms, share advice, and have fun!

(minimum 6 characters)

1 Bump

Very stressed and need some sort of answers.

The ultrasound said I am 6 weeks. I had a boyfriend and we never had protected sex, we had sex in May, and June. When we broke up I was vulnerable and I had sex with my best friend on July 4th. August 4th the doctor said I was 6 weeks. If the ultrasound is correct the baby is my ex boyfriends. I then got another ultrasound 7 weeks later that said I was 13 weeks, so that would still make my ex boyfriend the father of my child. How accurate is a 6 week ultrasound? and how accurate is a 13 week ultrasound? Thank you for everyone who cares to help <3 :)


Asked by Anonymous at 8:04 PM on Feb. 1, 2011 in Pregnancy

This question is closed.
Answers (13)
  • The measurements and markers they use to estimate fetal age are set to add 2 weeks. A 6 week fetus looks mostly the same no matter if your period was off or not. You had to have ovulated around July 7th in order to end up with a fetus that measured at 6 weeks, 4 weeks later... does that make sense? Your period may have been off, but your ovulation happened at a certain time no matter what. And that time was *likely* around July 7th.

    A fetus at 6 weeks looks VASTLY different than a fetus at 8 weeks. At 8 weeks you would have likely seen arms and legs, instead of just a blob. I would put my money on your best friend being the dad. If you had sex with the ex at the very, very end of June, it's *possible* he's the dad... but far less likely with the info you've given.

    Answer by LeanneC at 8:49 PM on Feb. 1, 2011

  • If you were 6 weeks on Aug 4th, that would put the estimated conception date around July 7th, which lines up perfectly with your best friend. You'd need a test to be sure, though...

    Answer by LeanneC at 8:13 PM on Feb. 1, 2011

  • Generally the earlier ones are more accurate because the early development is more drastic from week to week. At least that's what the tech that did my 20 week said.

    Answer by lizziebreath at 8:18 PM on Feb. 1, 2011

  • You could google image some pictures of a 6 week ultrasound and 13 week ultrasound. I'm sure there is a distinct difference.

    My first ultrasound was at 6 wks 5 days and all I could see was a black blob with a tiny little "bean" on the inside.

    And I agree with Leanne, that's a more than better chance that the father is your ex.... Wish you luck!

    Answer by ChelseATX at 8:20 PM on Feb. 1, 2011

  • You are already 2 weeks "pregnant" at the time of conception. A pregnancy is calculated by the start of your cycle which is typically two weeks before you ovulate (and are able to get pregnant). Unless the doctor was calculating gestational age (which they really just don't do to limit confusion).

    Do you know when your last menstrual cycle was?

    Answer by LeanneC at 8:23 PM on Feb. 1, 2011

  • If we had sex July 4th, that would only make me 4 weeks and 3 days at the time of the ultrasound though.?? Or can an ultrasound be 2 weeks off?

    Comment by Anonymous (original poster) at 8:18 PM on Feb. 1, 2011

  • Are you due around march 30th?

    Answer by LeanneC at 8:24 PM on Feb. 1, 2011

  • Yes I know what you mean @LeanneC but because my period was off due to the plan b pill i didn't have normal periods thats why they did an emergency ultrasound and that was the only thing they determined my pregnancy off of because my last period was too confusing.. So they didn't use my period at all. That's why when you said the 2 weeks pregnant at time of conception, I am not sure if that goes in my case because we didn't know my last period due to that bill.

    Comment by Anonymous (original poster) at 8:38 PM on Feb. 1, 2011

  • Yes I am due March 30th.

    Comment by Anonymous (original poster) at 8:38 PM on Feb. 1, 2011

  • Thanks everyone for the input. You've all made me feel better :)

    Comment by Anonymous (original poster) at 8:50 PM on Feb. 1, 2011