Confusion around due dates- how pregnant am i?!?!?

[faybe0988]

Hello all!!
Just looking for a bit of reassurance I think.
I am pregnant with my first baby, when I had my first midwife appointment, she dated me at around 12 weeks so put me forward for a scan- when I went for my scan yesterday the sonographer told me that I was measuring at around 8+2 (I saw the little heart beating which was very reassuring) so have to go back in 4 weeks time.
I used flo app to track period, ovulation etc and that puts me at around 9 weeks. (I never thought I was 12 weeks, but you have to trust the professionals!) I’m just so confused, has anyone else had experience of this or something similar.
I’m very anxious about the whole thing, which I’m sure is normal- but I really don’t want to worry myself silly about literally everything as I’m sure it’s not good for me- or baby!

Thanks in advance!

I reckon the midwife made a mistake. Did she use the little wheel thing? All she does when she does that is mark the first day of your last period in order to work out approximate dates - the same as you have. All she had to do was muddle the date and she'd have it wrong. Then at 12 week scan they 'date' you properly based on measurements of baby.

If you know the date of the first day of your last period then go with that til your next scan. It seems the amount of weeks you think you are is close to the amount estimated from the scan.

Could be worth ringing midwife and just saying oh you dated me as this but I know X date was my last period so I'm a bit confused. Just so your records can be updated.

Firstly congratulations!
Your midwife would have dated you from the first day of your last period; are your periods irregular?
When pregnant with my second I knew the dates I'd DTD so knew roughly how pregnant I was - when I went for a scan the dates didn't align and the baby was a couple of weeks behind my dates. I went back for my dating scan and baby had caught up with my dates. It could be something like this?

Midwives usually date your pregnancy from the first day of your last period. This is based on a woman having a 28 day cycle and ovulating 14 days before their next period. If you have irregular cycles or longer or shorter cycles, or even ovulate earlier or later in your cycle, it's totally normal for the dates to be out.

Being dated 8+2 when you believe you're 9 weeks is also totally normal. It's all based on measurements and at that size even a mm can make a difference. Any dating isn't 100% accurate, your given due date is always an estimated due date.

When you go back in 4 weeks, the estimated due date you're given at that scan will be the due date that the medical professionals go by. In the meantime they will go by the dates given at your early scan

I don’t know why they use those wheels, they’re really crap - I went to my scan 2 weeks early, I did say it was probably too early because my cycle is quite long and I often have a period every 5 weeks rather than four. But there’s not a huge difference between 8+2 and 9 weeks, so surely that’s about right then?

Yes the midwife's use a wheel which is based on a 28 day cycle. When I was dated and booked in for scan I knew it was wrong - I told them there and then that my cycle was 5-6 weeks, not 4, and then when I turned up for my 12 week scan I was only 10. I had to go back two weeks later for the NT measurements as I wasn't far along enough.

It's all fine!

That's what I dont really understand. My periods are regular, every 28 days. The app I used gave me the 9 week idea though and that's done the calculations with me putting all the data in. But the midwife said 12 weeks, when I use the NHS dating tool, that says 12 weeks too.
I suppose I'm just worried that baby isnt developing properly, although sonographer said everything looked fine. Tried getting in touch with the midwives and got nowhere with that.
It's my first baby so I'm anxious about everything!

Thankyou for replying!

OP what date was the first day of your last period?

You would of give your midwife the first day of your last period.. so they will go from that untill your dating scan. From my lmp I was classed as 14 weeks by time I went to midwife... I knew I wasnt as I have irregular periods and had previously done a test turned out I was only 9 weeks when I went for my scan (even the midwife knew this would be the outcome but they have to go from your lmp not what you think/or know) I just got re booked in for a proper dating scan a few weeks later. You wont need to ring your midwife as at your next app with her she will have all the updated information.

I'm really grateful for your comments
16th August was my last period

Op don't forget you're always down as 2 weeks further gone than you actually are because it goes off you last period

When you have your 12 week scan proper they'll date you then. I have long cycles and my date was moved back 10 days with my first.

@jesskir89 oh I actually didn't know that..

So do you guys think I'm worrying for nothing? I've never had a baby, dont know what to expect at all!

Do you make it 9 weeks since ovulation?

Is 16th August was your LMP then 12 weeks would be correct using the NHS method of working it out, but if you've been tracking and know when you ovulated and are working it out from that then trust your own. It's possible to have ovulated later but the midwife wouldn't know that info.

@codenamedutchess
I wasnt actually testing if I was ovulating, just going off the rule that the week following your period is a fertile week.
I suppose if the sonographer said 8 and a bit weeks, that's what I am. Perhaps I'm reading into what the midwife said too much as it doesnt appear to be an exact science!? Its not necessarily the case that I fell pregnant the week I was ovulating either? It's more likely but it's not 100%
My concern was that baby wasnt developing properly? I think I'm probably reading too much into things and worrying unnecessarily. Sonographer said she could see the yolk which identifies that I'm under 10 weeks and I saw the heartbeat! I should just relax!!

Thanks for all your comments

My last period started on 19 Aug and based on 3 scans I am 13 weeks today. Doesn’t seem possible! But I would go off your scan dates as they measure the size of the baby rather than the dates from the midwife. Congratulations!

Hi yes I had the same on my first pregnancy. I booked my 12 week scan for 12 weeks after my LMP (first day of last period), but it dated me at only 9 weeks. She said I probably ovulated very late. In the end I gave birth at 42 weeks... which was actually 45 weeks since my last period! So obviously they were right as they wouldn't have let me go to 45 'actual' weeks!

@marchingants
I cannot tell you how relieved I am after reading that message. That's all I wanted to hear. I thought I was abnormal and that there was something really wrong!