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Pregnancy

Talk about every stage of pregnancy, from early symptoms to preparing for birth.

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Original poster

How Do Some People Not Know How Far Along They Are?

27 replies

ballerini · 01/03/2018 20:55

I have read people saying they were further along than they thought at their dating scan and I wondered how this was possible.
Is this because they didn't remember the date of their last period or is it because the date of your last period is not always an accurate way of working out how many weeks you are?
Curious. Thanks.

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Lemontwist · 01/03/2018 21:03

At my scan baby measured at 13 +6. I was very sure of LMP date which would have put me at approx 12+2.
I can only put it down to either variations in ovulation/actual date of conception or perhaps that the dating is not an exact science. Who knows?!

ClareB83 · 01/03/2018 21:05

I think some people have long cycles, so they can't be sure when they ovulated. So although you would normally go by the date of last period it's not accurate for them.

I think also some people aren't sure when their last period was because they don't keep track.

And sometimes women get a bleed that's a bit like a period but wasn't so they're a month further along than they thought.

Also some women conceive after a miscarriage or giving birth without a period.

BertieBotts · 01/03/2018 21:07

It's because your period isn't an accurate way of dating a pregnancy, just a rough idea. And then yes also some people have long/irregular cycles, or they might have had light "periods" which were actually breakthrough bleeding.

And yes if I didn't track my periods I would have no idea when the last one was.

ClareB83 · 01/03/2018 21:07

Yes there's also that @Lemontwist - one of my twins measured bang on from my last period at all the early scans. But the other one was always a bit smaller, so if it had just been him they would have brought my EDD forward even though I know for sure my dates.

BertieBotts · 01/03/2018 21:07

Also if you got pregnant while on or just after stopping hormonal contraception, the period date might be missing or inaccurate.

Chienrouge · 01/03/2018 21:08

My cycles are anything from 26 days to 54 days. LMP is fairly useless in that situation.

yougetwhatyougive · 01/03/2018 21:12

I don't get periods every month, somehow knew I was pregnant each time very early on.

GummyGoddess · 01/03/2018 21:22

I know my dating scan is out by a few days because I know when I ovulated as I get clear ovulation pain and I know when I had sex. I'm sure babies can't all grow at the exact same rate, there must be some small variations which would give a week or so discrepancy.

Rainshowers · 01/03/2018 21:23

I didn't have a period for about three months before I got my positive pregnancy test so I had no idea until I had a scan how far gone I was. Similar happened the first time round with DC1-my cycles are just all over the place.

Chienrouge · 01/03/2018 21:24

Oh and with my second, I was on the mini pill and was still EBF... I hadn’t had a period since before DD1 was born! So had no idea how pregnant I was.

CaviarAndCigarettes · 01/03/2018 21:48

When I was pregnant with my first I had been diagnosed with pcos and rarely had periods. We'd gone without contraception for five years and nothing had happened so we didn't even suspect pregnancy until I fell over after two glasses of wine. I was 9 weeks

teenybean · 01/03/2018 21:58

I was on the pill & hadn't had a period for about 6 months before I fell pregnant with my son, I found out at 10 weeks & we had only done a test because I fainted & mil laughed & said I was probably pregnant!

bigfatbuddha · 01/03/2018 23:04

I have pcos and my cycles vary from 5 weeks - 7 months. Try to date that.

punkpuffin · 01/03/2018 23:12

I don't really get periods, I have one excruciatingly heavy one roughly every 6-10 months. I was told I probably wouldn't conceive easily because of it. But I had all my dc almost immediately to Drs surprise. If I had dated from my last period I would have been at least 6 months pregnant. I had early dating scans with all of them.

TinoTheArtisticMouse · 02/03/2018 06:02

They moved me forward 4 days at my 12w scan, despite having regular periods, knowing my lmp and having +ve ov test on cd14.

Baubletrouble43 · 02/03/2018 06:17

My dd1 was conceived ( too soon) after a mc and my periods had not settled down. Plus my head was all over the place. And she was small. She seemed to be 2 weeks late but I think she was bang on time.

RefuseTheLies · 02/03/2018 06:23

I had ivf so I know pretty much to the hour when my daughter was conceived

However, she was always a bit bigger than she ‘should’ have been at my scans, so they were constantly trying to adjust my dates until I pointed out that I’d had fertility treatment so knew precisely how far on I was.

GnomeDePlume · 02/03/2018 06:29

I found out I was pregnant at 17+5. Had copper coil and irregular periods. DC3 was born practically clutching the coil so it hadn't come out just hadn't done its job.

Had DC(3) and DC(6mths) so we were probably asleep when we DTD!

TeaAndPjs · 02/03/2018 07:09

My friend got a dating scan thinking she was 8ish weeks but not sure and she was 19, she was still getting periods 1st few months so didn't realise

SPARKS17 · 02/03/2018 10:12

I was 3 weeks out despite knowing the exact date of my last period as I was using an app. No one has given me an actual answer as to why that is other than it might not have been a proper period (it lasted 5 days and felt like a "proper" period!). Who knows, it was nice to find out I was a further 3 weeks along than expected!

Oysterbabe · 02/03/2018 19:33

My cycles were still irregular after stopping the pill. I was 2 weeks further on than I thought.

springmachine · 02/03/2018 19:41

I had PCOS and actually hadn't had a period for 2 years before trying pregnant.

I therefore had no idea how far along I was

pastabest · 02/03/2018 19:43

I've had really heavy ovulation bleeds with two of my pregnancies (no 2 and 3) that could easily be mistaken for a slightly lighter period. Pregnancy no 2 I didn't start feeling sick until I was nearly 8 weeks pregnant whereas in pregnancy no 1 I started to feel sick at 4 weeks. So it was a bit of a shock at the scan to find out I was 4 weeks further ahead.

Pregnancy no 3 I had no symptoms at all, so if we hadn't been actively trying/testing it's likely I would have been 4 weeks out with that one too.

pastabest · 02/03/2018 19:44

I mean implantation bleeds not ovulation

KochabRising · 02/03/2018 19:48

I just had my dates moved to a time that is physically impossible - told the sonographer this and got the usual patronising spiel about you might not have realised dear and foetal growth is exact at this stage.. yadayada.
Told her that we’d only shagged once that month due to being away travelling with work then both of us being ill...
She still didn’t believe me and so baby is now divinely conceived an entire week before he possibly could have been. I know my dates are correct and hers are a week out (a whole week! At 12 weeks ffs..!)

Anyone who can explain that to me Id love to hear 😁

Plus yes all the reasons above. You might not have regular periods, you might not have ovulated when you think you did. Having IVF or only shagging once is a pretty good reason to say that while conception could have been later, it certainly can’t be earlier!

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