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2 Bumps

When i went to my appt..

i checked online the due date calculator from my last period and it said aug. 29th bc my last period was nov. 22nd. but when i went to the dr today they did an ultrasound (the vaginal one) and they said im about 9 weeks and 3 days but i thought i was further then that bc when i had my last period. so can they possibly got it wrong when my due date is?

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Anonymous

Asked by Anonymous at 12:52 AM on Feb. 15, 2011 in Pregnancy

Answers (9)
  • Well, they usually go based on your LMP not the ultrasound. If you are absolutely sure of your the day your LMP started, then your OB will go with that date. I don't know what to tell you except ask them.
    Katie80620

    Answer by Katie80620 at 12:55 AM on Feb. 15, 2011

  • They were wrong with both of my children so yes they can
    Kathy675

    Answer by Kathy675 at 12:57 AM on Feb. 15, 2011

  • ummm my LMP made me to be at 11 weeks 4 days but i was only 9 weeks 4 days according to the u/s. My ob is using the later date because im measueing up to be exact with it. according to it im now 28 weeks 1 day due may 9th instead of April 25.... They can be off up to 2 weeks either ahead or behind as well tho.... guess the only way to know for sure is when the baby comes out till then go with what ur ob says...
    TatymMommi

    Answer by TatymMommi at 8:44 AM on Feb. 15, 2011

  • I had the same situation. I went in and thought I was 7 weeks and they did the vaginal u/s and said that I was only 5 weeks. I didn't think that was possible but they said I must have ovulated really late and went back a week later to see the heartbeat and was measuring at 6 weeks. So my Dr. is going by the u/s date!
    saysmom

    Answer by saysmom at 9:16 AM on Feb. 15, 2011

  • i had to periods in june and im sure i got pregnant in between or right before my second one but the ultrasound says i got pregnant the beginning of july...so my dr is going with march 31 st instead of march 16 th like i think..either way it doesnt matter he says if i go early he wont be surprised or upset and that it really doesnt matter cuz it will all end in a sweet little baby so dont stress it and just go with it
    ahsot1230

    Answer by ahsot1230 at 11:08 AM on Feb. 15, 2011

  • Yeah, they can be wrong. I had spotting at what I thought was 7wksaccording to lmp , turned out to be 5.5 wks. according to u/s. My c-section is scheduled for 40wks exactly with my LMP, so I'm not too worried.
    BisketLiss

    Answer by BisketLiss at 11:10 AM on Feb. 15, 2011

  • Let me see if I can explain the math here,
    Doctors usually calculate your due date based on your last period. You didn't get pregnant on the first day of your last period. You got pregnant about 2 weeks after that. Take into consideration 1 week for your period, then there is usually 1 week between the last day of your period and when you are fertile again.
    So, The doctor will calculate your due date based on 18 weeks of pregnancy plus 2 weeks between your last period and when you were fertile. = 40 weeks after your last period.
    Therefore, both your doctor and your ultrasound are correct.
    Dalimonster

    Answer by Dalimonster at 11:10 AM on Feb. 15, 2011

  • That gets complicated.

    Unless you have a regular 28 day cycle, the LMP will not be accurate and the ultrasound will be closer to the actual date.

    If you do have a 28 day cycle, then I would say that they US is wrong or the technician that read it didn't do a good job.

    One more thing to consider is that an US can be off by as much as 2 weeks.
    Jademom07

    Answer by Jademom07 at 11:11 AM on Feb. 15, 2011

  • sorry, that was supposed to be 38 weeks of pregnancy plus 2.
    Dalimonster

    Answer by Dalimonster at 11:11 AM on Feb. 15, 2011

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