How much do most people's dates change (if at all) at the 12 week scan?

[porpentine]

I ask because I wanted the nuchal scan but my appointment's not until I'll be 13+4 - which seems cutting it a bit fine if I'm a couple of days out (and at a previous scan I was 2-3 days further on than they first thought).

So are most people pretty accurately what they thought they'd be at their 12 week scan, or does it change a lot? Just trying to get a sense of how likely it is that they'll be able to do the nuchal...

Was given a date 10 days later with DS. He then arrived on the original due date according to LMP! With this one date 3 days later so not much in it.

I was told I was further along by 5 days

My first changed by 4 weeks!!! The 2nd was bang on my date and the 3rd was 3 days difference.

I had my scan at 13+6 (I thought). Was actually 14+1 but the baby was slightly too big for the NT scan (can only be done within certain measurements). Now have to wait for blood tests instead...

This time I was put forward 1 week. Cant remember the others

Mine changed massively with DS, midwife estimated 10th July but the scan showed 23rd August. This time around she refused to believe I'd been having a six week cycle since my mmc last year and worked my estimate due date out based on a four week cycle as 20th August, I told her I thought 15th September - scan showed 11th September so I was closest.

both DS & this one were brought forward by 10 - 7 days respectively. and i know when we DTD so know my dates were right,

DS was born 10 days earlier again so 3 weeks by my dates, I figure when this one's finished cooking it will pop out. :)

1 day, although it could have easily been 4 weeks out if I hadn't had early scans for bleeding.

My due date was moved forward 6 days - not sure how that happens - I was keeping note of dates so I guess my cycle must be different than I expected. Nice to gain an extra week almost without doing anything!

Mines was changed to the 8th to the 18th of January at my 12 week scan. So 10 days.

Sorry from the 8th to the 18th duh!!

mine changed by one day - it became one day earlier.
that's probably mroe due to the fact that my cycle is just under 28 days.

oh, and my scan was 13+3 on the original dates.

Mine changed by 4 days with ds. Changed again at the 20wk scan but they decided to keep me where I was! Wish they hadn't now as he was 11 days late and would have been only 8 if they had changed it again.

I was supposed to be 12 weeks and measured for 14.5 weeks. I have irregular cycles though.

With DS the MW estimated me as due 10th July based on LMP, my first scan he was just a blob and nowhere near 12 weeks so had to go back at a later date and my due date was changed to 23rd August.

With this one I estimated 15th September based on a six week cycle following a mmc, MW worked it out based on a four week cycle and my official estimated date was written down as 20th August. 12 week scan said 11th September so I was write.

I think if you're fairly sure of when your last period was and when you had sex that month and when you got your BFP (which is normally around 2-3 weeks give or take) then your actual due date according to the scan shouldn't be too different to the estimated due date worked out by the MW.

Forgot I'd already posted on this

Mine changed by 4 days.

My EDD is 19/12/11 but their EDD is 11/12/11. This means we conceived before we even dtd!! Must have been an immaculate conception.

I'm 100% confident that my dates are correct.