How Accurate is Your Pregnancy Due Date?

During your first prenatal visit that confirms pregnancy, your doctor will also provide you with something pretty significant, which is your DUE DATE!

This is a special date, that in your mind will become so solidified with meaning that you will spend the bulk of your time over the next nine months in serious countdown mode to this particular ONE DAY!

But just how accurate is your pregnancy due date?

When your doctor gives you a due date, they are taking into consideration a variety of factors. The most important of which is the date of your last menstrual period. From that date, they will try – using broad generalizations, to figure out when you ovulated – and thus exactly when you became pregnant. Even if you know the exact date that you became pregnant – you might be off by a few or more days to the time when implantation actually occurred. Since every woman’s body operates on its own unique schedule – using the date of your last menstrual period to come up with your due date, is quite simply NOT 100% accurate and is just the best generalized way to estimate how far along you are and when you might deliver your baby.

Additionally, as you progress through the pregnancy and your doctor begins to measure the size of your uterus (fundal height), uses Doppler technology and Ultrasound to check on the progress of the baby, your due date may change considerably. In many cases, your due date may change several times throughout your pregnancy. Sure, this can be frustrating, and even though you know in the beginning of your pregnancy that your due date is only a mathematical calculation not a certainty – you might find yourself frustrated. The reality is that only as few as 5% of women give birth within a day or two of their ‘due date.’

In fact, the good news is that around 80% of all women deliver between the 37th and 40th week of pregnancy, which means your baby could be here sooner than you expect. And likewise, most physicians will safely allow a woman to sail 2 weeks past her due date if she and the baby are doing well before initiating any sort of labor inducement.

One of the beauties of pregnancy and childbirth is that we as humans, learn to recognize that we do not have control over every little thing in our lives. You’re little one will arrive on exactly the day when he or she is ready to come. While keeping track of your due date gives you something to look forward to, and count down to – you shouldn’t regard the date as something etched in stone.

Written by Stef, Mother of 4 @MOM-Spirational

This information is not intended to replace the advice of a trained medical doctor. Health & Parenting Ltd disclaims any liability for the decisions you make based on this information, which is provided to you on a general information basis only and not as a substitute for personalized medical advice. All contents copyright © Health & Parenting Ltd 2018. All rights reserved.

Team Health & ParentingHow Accurate is Your Pregnancy Due Date?

Comments 29

  1. Ilona

    now I m. 41week pregnant, still Waiting ( due date was 16th Of January)….:
    26 Of January I m going again for induction.

    Exated, stress and Happy for my first baby.
    All things are ready for New family member 🙂

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  4. Angele

    Hi guys!! My name is Angele I am 9 weeks and 1 day. My baby is measuring as of now 8 weeks but the doctor said she will keep it at when my last first menstural started BC everything looks great and only a week behind. The nurse said that I might have ovulated early than what we thought but that normal when u on birth control. This is my second pregnancy my little boy is now 5 going to be 6 July 20th. I congratulate all the mommies on here and the best wishes!!!

  5. Rach

    This is absolutely true.
    We estimated I would be around 9/10 weeks pregnant when we found out. 2 weeks later we went for our first ultrasound scan and he was there and measuring 15 weeks and 5 days! How we didn’t know, I have no idea!
    Now I’m sat here at 41+1 and extremely fed up, painful and extremely emotional.
    Please ladies, don’t set your heart on the date they give you, I did, and after my 3Rd sweep everything is exactly the same and I’m due to be induced 23Rd of December. It’s a long and arduous journey becoming a mother, take your time and enjoy the peace while you can!

  6. latina

    Hi ladies. I was on the pill When i first found out i was pregnant @ around 7wks. I was heavily bleeding, had constant pain and was told I had an empty sack…. prior to this pregnancy I had a miscarriage/stillborn at 25.4wks so was naturally scared. I had gone for emergency scans and they found no cause for the bleeding and weeks later it slowly eased off and eventually stopped. There was a growing baby present 🙂 The pain through out this pregnancy reminded me of the miscarriage, doctors have assured me it could be a scarred ovary hence the pain…. I had gone for another scan 2wks ago and it was said my baby was small and her growth is limited but not to worry cos baby has a strong heartbeat and very active. . I then get told my wee girl’s growth could have been affected due to the earlier bleeding. I’m getting rescanned in another 2wks with possible early birth. I’m am now 28wks pregnant and feeling overwhelmed…. has this happened to any other expecting mums???

  7. Charlie

    Hi all I’m 20 and this is mine and my boyfriend (18) first baby 🙂 I had three diferent due dates one for the 6th of September 2015 one for the 16th and now the midwife and doctors have come to the due date of the 18th of September.. Now we have a accurate due date I’m so excited to meet our little boy.. Best wishes everyone!

  8. rita

    hello I’m new to this um my name is Rita I’m 20 years old and I am 6 weeks and a day I have been feeling nausea n stomach pains also back pains um this is my 2ed child 1st one had a miscarriage at 3moths and 5days hope this one goes good.

  9. Dominique

    My husband and i thought we were 9 and a half weeks along when we went for our dating Ultrasound. Turns out our baby only measured to be 7 w 2 d. Drastically changed the due date. Turns out I ovulated closer to the start of my next menstrual cycle. Every woman is different!

  10. Alexandra

    You all are wonderful people. Sorry for your loss Emma. I hope all goes well tho time around. Try an stay positive hunnie. Xoxoxo 29 weeks so far ! Xxoo

  11. Emma

    It’s good to read all your advice ladies. I had a miscarriage in January (I went for my dating scan and was told baby hadn’t developed after 6wks 3 days!) I am now 6wks and 3 days pregnant again and it’s my birthday! Hoping and praying all is ok this time round. Thankfully they are giving me an early scan on Monday so just got to get to then. Crossing everything all is ok and I can relax a little. Love and positive thoughts for you all. xxx

  12. April

    Congrats on everyone’s pregnancy. I am a gestational carrier for my friends and apparently am in the 5% that gives birth near my due date. My son was 1 day late and daughter 1 day early. Told my friends I ll give birth on time w/ their child.

  13. Fifi

    I’m a sonographer (the medical professional who does the ultrasound scans). My dates are exact (IVF) and my first ultrasound at 6 weeks 2 days measured 5 weeks 4 days. One week later, my little one was measuring correctly at 7 weeks 2 days. Good figure. You shouldn’t change dates after the first trimester because that can cause you to miss a small or large for gestational age baby.

  14. Ashley

    I am pregnant with my forth child 10 wks I was told going for my first ob apt tomorrow. So excited and nervous I hate the pap smear part. I am hoping for an ultrasound though that would be awesome. Fingers crossed.

  15. Kendra

    Hi lady’s , i am 10 weeks pregnant today .. I had spotting in my beggining weeks , which my doctor said was normal .. As long as there’s no heavy bleeding like a Menstrual cycle everything is fine .. My first prenatal visit we only saw the sac .. Went back to the doctor and there was my baby with a strong heartbeat .. Everything will be fine lady’s , stay calm and keep positive .. In the in you will have a beautiful bundle of joy .. Good luck to all and God bless

  16. Hannah

    Hi Ladies, I also needed an early emergency scan due to light spotting. Went there thinking im 8 weeks but after the scan was told i was actually 9 weeks dont know how that works out?

    Good luck to all you soon to be mummies and try not to stress over bleeding/spotting even though it is very hard. Stay calm an relax into the pregnancy x

  17. Jill

    Hi candice I now know that feeling we had a 2nd scan today following my previous posts and there it was a heartbeat 6 weeks 3 days my husband and I are so relieved just got to stay positive and am sure we will be fine thank you to everyone for there best wishes x

  18. Candice A Machelm

    I went for mt visit and the baby’s heart is beating, my husband couldn’t stop smiling when we saw that on the ultrasound!

  19. Gulin Fellows

    Good luck Candice I’m sure you’ll be fine! Don’t forget every pregnancy is different! Let us know!

  20. Candice A Machelm

    Hi, I had a mc in march, but I’m pregnant again! So excited and nervous at the same time! My first prenatal visit is today ……. So far so good with the pregnancy, previous pregnancy I started spotting at 4-5 weeks. I’m now 6-7 wks and no spotting, thank God! But the neausea is worse then before. I just hope everything goes well today….

  21. Jill

    Just an update my hcg levels have gone to 35628 which is good just hope we see something in the gest sac on Friday x

  22. Gulin Fellows

    Mine was over 20.000 when I had the scan and it was too early to see anything. So it’s probably what we thought and you are still at very early stages. If your hcg doubles every couple of days you’ll be fine. Let us know!

  23. Jill

    Just an update I had bloods done the result today are hcg level of 16641 doctor said its good news so having them re done on Monday staying positive x

  24. Amy

    Hi Jill,

    I hope all is well!
    Let us know!
    Thinking of you and like gulin says try and stay calm and not stress as worse thing you can do.
    Be positive x

  25. Jill

    Thank you for your reply I have had no more bleeds since Monday I am resting and trying to stay positive.

  26. Gulin Fellows

    Hi there, the same thing happened to me dont worry, you probably ovulated a few days later than you think. I went for a scan I was 6 weeks and we could only see the gestational sac no fetal pole or yolk sac, my doctor told me it’s very normal and that we should wait for another 10 days to see “something”. I was stressing like you but pregnancy is all about waiting! After 10 days here my baby was with a heartbeat! It was measuring 4 days behind its date which means i ovulated later in my cycle. At the very early stages of pregnancy even 1 day makes a huge difference. Now stop worrying because it is not good for you!

  27. Jill

    According to dates I should be 6 wks 2 days I had a small bleed at the weekend and doctor sent me for a scan yesterday the scan shows the gestational sac but no yolk or fetal pole the doctor said it is either that I am earlier than thought or it has stopped progressing They are re scanning in 10 days have had no more bleeds in the past 2 days really scared as had mc in feb has anyone experienced this ?

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