Wrong Due date?

[Deanna9]

I have a question about my due date, I and my partner think it's wrong going on what we know about ovulation.

Period on the 30th Sept 17- 3rd Oct 17

Sex on the 6 oct 17

Sex on the 20th oct 17

Period on the 21st oct 17- 23rd Oct 17

This makes conception after the 20th impossible so how is my due date the 6th sug 18.

Ive not had sex at all since the 20th of October so I know I can't have gotten pregnant after that.

I'm pregnant with my 10th baby and we had an early scan at 7 weeks which means I conceived 5 weeks before. Just because they originally go by LMP doesn't affect how many weeks they say you are at a scan. At my 9 week scan I measured 9 weeks but I'd conceived 7 weeks ago. Pregnancy lasts around 40 weeks but those first 2 weeks you aren't actually pregnant!

Baba cannot measure 7 weeks and actually be 5 weeks. In that case what's the point of measurements at all and y change your due date due to measurements at scans.

The gestational age of the baby includes the two weeks when you are not pregnant.

I had my 7 week scan on the 28th Dec, my last period was the 9th November, I conceived around the 23rd November so I had technically only been pregnant for 5 weeks at the scan but measured 7 as they add on 2 weeks as they do with all scans!

So my gestational age is 31 weeks, my baby's age from conception is 29 weeks.
So by the 6th Aug my gestational age will be 40 weeks but my baby will only be 38 weeks.

Lmp on the 20th oct gives me a due date of 20th July so gestational age at 40 weeks which means my babys age would be 38 weeks on the 6th July.

So pregnancy is classed as full term at 37 weeks but baby's age would actually be 35 weeks.

So full term gestational age is anywhere between 37 and 42 weeks and babys full term age is anywhere between 35 and 40 weeks.

Is that what your trying to tell me? Because of that's right why are doctors so concerned about gestational age?

Ok, now there's numerous scans all proving you are wrong. Those early scans you've now mentioned prove you conceived mid November and due date around 8th August. If you are confused just try counting the weeks until you get to 40. If 20th of Dec is week 7 then 8th August is week 40. You can do the same counting from week 5 at 6th December. You can also Google 'when did I conceive?'. There are several websites that take due date and give you a suggested conception date.

It is absolutely correct that due date is calculated by adding 40 weeks to the first day of your last period (that's going by an average 28 day cycle). Your period and ovulation count as the first 2 weeks. Yes technically baby has been created for 38 weeks at 40 weeks.

Please just google this if you don't believe what people are telling you. I'm so confused why you didn't know this if you have been pregnant before.

Yes a "40 week" baby has actually only existed for 38 weeks, but it's irrelevant as that's the universal way of measuring, so they still mean the same thing. Due date is 40 weeks from lmp, so 38 weeks from conception. All your dates match up, other than the date you say you last had sex. Baffling!

Because I wasn't in contact with sperm after the 20october, if an egg was fertilized around the 13th Nov which is after my first positive test so not possible.

Sperm lives 5 days max so till the 25th Nov so it not only survived the max days, it's also managed to survive me bleeding for 3 days.

An egg cannot be released during a bleed, get fertilized and then float around for 18 days max or 13 days minimum.

I'd have had to have had that egg fertilized by the 25th and implanted instantly and then I defiantly wouldn't have gotten a positive test result only 10 days later.

I don't care when the Internet says I ovulated because either way for that cycle it's not possible from what biology and science say.

And I have a 21 day cycle not a 28 day cycle.

Even if I push the last time I had sex back till the 30th Oct I still can't have, released an egg be that on the day or 5 later and implanted it to start creating hcg and have a positive test on the 10th. Its not possible the tests just don't work that early.

Unless both me and my partner have super baby making powers we aren't aware of.

I know for definite we didn't have sex or any sexual play of any kind after October.

I always get positives 10dpo on occasion 5 dpo.

"Even if I push the last time I had sex back till the 30th Oct"

So does this mean you aren't quite as sure as you were at the start of the thread about when you had sexual contact?

Perhaps you're also misremembering when you POAS

I agree with the other posters who say that your ME would have booked your 12 week scan for what she thought was around your 12th week based on what you said to her then, and that the 12 week scan was indeed in the 12th week. So can you remember what you said then?

If you didn't know, or your MW found what you said implausible/confused, then she would have referred for a dating scan, not just plucked a 12 week guess, one cycle out from your dates, from thin air.

And so out of curiosity when my son was born at 37.5 weeks he was actually 35.5 weeks? And term is only in conjunction with gestational age?

And a baby born at the earliest of gestational age 24 weeks is actually a 22 week old baby?

If it's safe for us to go till gestational age of 42 weeks making baby only 40 weeks, y can we go till 44 weeks gestational/42 baby's age when the placenta only starts to develop after the egg has implanted as far as I know anyway.

How can development be even slightly accurate. A baby's lungs mature after 37 weeks that why Premature baby's get steroids but if a baby's born even after 37 weeks gestation it's not actually that age so how does that work.

No I defiantly know the date I last had sex, was making a point that it still wouldn't be right if it was later by a week.

I told my midwife the 30th sept and the 20th oct as two possible dates and she booked based on that and the 7 week scan. I explained then that I had only had sex in that month window from my son being born and my positive test too.

She told me I'd be anywhere between 10 and 14 weeks on the scan and left it at that. Why she would think 14 weeks if she wasn't taking the 30th Sept into consideration I Dont know.

Either your dates of sexual intercourse are wrong or you need to change your name to Mary and sell your story to the tabloids.

Ok, so this is quite a lot of the source of your misunderstanding. Yes, they adjust due date at dating scan, but they still add two weeks onto the conception date - so they do it as if they're finding you a more accurate LMP date. So if you 'measure' 7 weeks, that means you measure 5 weeks from conception date. If they measured you 12 weeks at the scan they're saying it's 10 weeks since sperm met egg. No one in the NHS ever, ever works off actual conception conception/ovulation dates - they always add these two weeks on. Otherwise a pregnancy would last 38 weeks, not 40.

My dates of sex aren't wrong, I write everything down and my son was in our room still at that point so sex was planned not done spontaneously.

And so out of curiosity when my son was born at 37.5 weeks he was actually 35.5 weeks? And term is only in conjunction with gestational age?

Yes, that's exactly right.

How can development be even slightly accurate. A baby's lungs mature after 37 weeks that why Premature baby's get steroids but if a baby's born even after 37 weeks gestation it's not actually that age so how does that work.

Well, when we say a baby is 37 weeks we mean that it's 35 weeks since sperm met egg - but that's true of all 37 week babies, so how can you think that it makes a difference to whether or not they need steroids. We still know how old they are and at what gestation babies do and don't need steroids, the fact that the pregnancy is 37 weeks and the fetus is 35 since conception doesn't change that.

Do you not believe what numerous people have told you about how pregnancy is dated??? You still seem to be questioning when the 40 weeks is counted from! Why can't you just research this yourself rather than repeating the same questions over and over again! It is fact and not something we've collectively chosen to make up.

A baby born at 37 weeks is 37 weeks as pregnancy is dated from first day of last period. You choosing to count that as 35 weeks is irrelevant as that is not how pregnancy is calculated.

I'm not going to say you are making up when you had sex as you clearly believe it's true despite what scans say. You can surely see why people are doubtful when your basic understanding of pregnancy is so limited. I would suggest you alert midwife to your concerns and also book a private scan to check babies size.

LISASIMPSONSBFF, I've accepted that, I now understand that but 10+4 weeks before that scan is the 20th nov which is 10 days after my positive test so explain that.

7+3 week scan puts baby at 5 weeks conception on the 18th Nov,I 8 days after my positive test.

5 week scan put baby at 3 weeks conception on the 15 Nov.

The 20th November is also a month after I last had sex so again how does that work.

Going back 12.4 weeks would make my lmp the 2nd of Nov too which is way wrong.

Neither of those make any sense on any of my dates and I definitely know the last time I looked like Id had a blood bath and felt like I'd been kicked in the stomach repeatedly.

They also don't make any sense with what the midwife said or that your saying.

The 7 and 12 week scan could only possibly be out by a few days at most, something doesn't add up!

OP it's you that doesn't make any sense not the situation. As numerous people have already said to you, you need to speak with your midwife or doctor rather than keep asking everyone on here to "explain" something to you that can't be explained in any way that you would be willing to accept. Whatever the situation your baby measured 12 weeks at your 12 week scan and 20 weeks at your 20 weeks scan at that is all they are going to be concerned with really. In a few weeks time you are going to have a baby, I would suggest you start to look forward and focus on this rather than becoming fixated on something that you really can't do anything about at this stage.

And using the NHS due date calculator on an lmp of the 20th October and a 21 day cycle it gives me a due date of 20th July making me 33 weeks pregnant not 31.

That's a 2 weeks and 3 day difference in due dates.

I'm asking because I'm curious, I will be talking to my midwife too.

No one's saying that your scan dates match up to when you think you had sex and got a positive test. They're saying that every single scan date - performed by multiple different medical professionals - agrees, so the error is far more likely to be yours than theirs.

There is no such thing as a viable fetus that measures 7 weeks (5, by the way you're insisting on counting) when it's really 11/12 (9/10, by your count). If you're certain about your dates that is always a sign of miscarriage. Evidently, and happily, your pregnancy continued, so the scan can't have been off by that much.