Dates changing within a week?

[hollydays7]

I had a private scan 14th March which measured me at 9+6 which was spot on with when I'm pretty sure I ovulated. Today I went for NHS dating scan and they put me at 10+5 which just doesn't add up, I fully expected to me 11+1 today going by private scan and ovulation. Sonographer seemed dismissive of private scan and said they are inaccurate anyway (even though it matched when I ovulated much more) I have to go back next Monday as it was too early to do nuchal tests I'm just worried and concerned thinking about how the dates can change like that in only a week and am I likely to stay the same as today's dating next week or catch up and match private scan? Sorry this is my first baby and it's a worrying time!

When it comes down to it there is barely a difference between 10w5 and 11w1. 2 days is a fraction of a mm, it’s really nothing to worry about.

I had the same thing but the 12 week NHS scan put me a week further along, which didn't match my dates or early scan I had at 7 weeks.

I had another private scan at 16 weeks and then the 20 week scan. Both matched up to the 12 week one.

Don't worry about it, when they are that small you are talking mm.

I've mostly heard of people being further along than they thought but not many behind which is why I was worried, I would of found out I was pregnant at only 3 weeks if these dates were to be correct which seems crazy

That isn't much difference. And you'll usually find that you could get a different sonographer to re scan you 5 minutes later and get a different result too.
The way they measure, there's such small movements within the lines that not even a millimetre movement/placement of the grid can result in even a weeks change.

Also the reason why they don't tend to change your due date until your 12 week scan

@hollydays7

I've mostly heard of people being further along than they thought but not many behind which is why I was worried, I would of found out I was pregnant at only 3 weeks if these dates were to be correct which seems crazy

2 out of my 3 pregnancies that got to 12 weeks, I've been out back 4 days. My 3rd one I was put back 1 day

Babys have growth spurts. In the early stages they are also so small that it is easy for the sonographer to get the measurements slightly out giving you different dates.
At my dating scan the sobographer picked up measurements putting baby at 13+3 but settled on 13 exactly after a few attempts. So you see a single scan can throw up different dates especially with an active baby.

I conceived through IVF and they still kept on changing my dates although it couldn't have been any more accurate. I raised it as didn't agree with it but I was told that up until 12 weeks, they base dates largely on baby' le measurements. So measurements will decide how old baby is. After that, they will just stick to one date and any future measurements of baby will be against that one date. They messed mine up so much that I had to have monitoring for small for gestational age, where's if they kept my original IVF due date, everything would have been fine! Sorry, rambling on now

I had three early scans and the dates changed at all of them but all has been ok with the pregnancy. I really wouldnt be worried about 2 days I was told when scans are that early it can be anything up to a week different and they still don't worry

I'm sure it's all fine

I had a reassurance scan (due to previous second trimester loss) at 15 + 3. The babies leg measured 15+6, another part 14+6 and another 15+2. It was all around the right dates, like when they pop out babies don't grow in a linear fashion and have growth spurts and aspects of them that will be different e.g. long legs 😊