Measuring a week behind

[Murrrrcat]

Hey,
Last week I went for an early scan mainly to put my mind at rest after missed miscarriage in October.
So at my scan thankfully baby was in the right place and had a heartbeat and little wriggerly arms and legs but I was meant to be 10 weeks 6days. But the sonographer measured the baby at 9weeks 6days, the confusing part is when i got a positive test it should not of been positive according to the dates.
I have another scan in around 2 weeks but i just can't put my mind at rest

I've had this twice where scan dated things several days out from my dates. DS1 measured exactly as he should have throughout and was born one day off his due date. Currently pregnant with DC3 and the same happened. I think if may be to do with the actual date of conception being able to vary from the date you actually dtd and the sperm can hang about for several days before conception takes place.
The fact you've seen your little bean on scan with heartbeat is really positive and massively lowers risk from now.

Im in a similar situation... went for a scan due to previous mcs expecting to be 7w and she measured me at 5+5 however we did see two (!) heartbeats so that did reassure me a bit. I would have only got a positive test at something like 8dpo by her dates which I suppose is possible and it was very much a squinter plus my cycles have been pretty irregular (24-32days) and I have a 10 day LP so it could add up, are your cycles v regular? I think the fact you saw a heartbeat is a good sign.

Thank you for replying :) Yeah my periods are regular, i took the test like on the day my period was due just on the off chance we've been trying for a year and a half & unfortunately had two unsuccessful pregnancies, my due date slightly changed with my son, but i didn't think to much about it but this time i was very confused a about the postive test and then I'm a week behind & omg congrats! & good luck! & seeing the heartbeat made me feel a millions times better I think I'm worrying over nothing really

I had to have an early scan which put me a week behind where i thought i should have been but then when it came to the 12 week scan I went forward 4 days

There’s a 5 day margin of error anyway, and you could easily have conceived/implanted a few days later than you thought.

With DD I consistently measured 5 days despite knowing the date of conception (DH was working away and was only home once!) and she’s still very little aged 4. I’m 15 weeks now and measuring a little behind my dates but as I conceived soon after miscarriage my cycles could have been off. Once you’ve seen a heartbeat chances are very good.

Thank you everyone for your replies and personal experiences, really appreciate it, i feel abit better :)