Dates don't add up - any ideas?

[Prinpo]

Hello, I'm currently 9+4 according to my lmp. For various reasons, I've had my third scan of this pregnancy today which has dated me as 7+3 (ish). The previous scan which I had last week also put my dates about 12 days earlier than I make them. I'm pretty confused about why this could be happening. I got a (very faint) pregnancy result the day before my period was due and a much more definite one the day after so my reasoning is that my dates can't be more than a few days out, otherwise it would mean that I'd had a positive pregnancy result when I was hours pregnant! However, the consultant was adamant that they will go by the dates of the scan.

My reason for wanting to clear up this discrepancy is that I want to book myself in to have a nuchal fold (I'm 38) and, having spoken to the clinic, I need to be clear about my dates. Also, I'm concerned that the baby / sac is measuring small and worried that it means something is wrong.

I hope that makes some sort of sense! If you can shed any light on this I'd be really grateful.

[SparklyGothKat]

well according to my early scans I had a postive test when I wasn't even pregnant Early scans are often out, I would wait till 12 weeks and see what happens then, when do you need to book the Nuchal fold scan?

[Prinpo]

Well, there's a window of opportunity between something like 11+3 and 13 weeks (can't remember exactly). However, I have to go to London for it and it needs to be booked. When I spoke to the clinic they said that sometimes appointments were available at short notice but that it's best to book.

[Prinpo]

Lol about positive result when you supposedly weren't pregnant, btw. Pretty impressive.

[Qally]

I had exactly this happen to me - just book so you're safe for both dates? They swore blind from scans that I was due on the 20th Nov. I knew it was 5th, because I knew when I'd conceived. DS arrived at well over 8lb, not a scrap of vernix and fat as butter on the 2nd. The midwives found the suggestion he was anything but thoroughly cooked hilarious, but I'd had to argue to get the scans etc done at a time that worked for both edd all through.

I had morning sickness from 3 weeks pregnant if their dates were right. I pointed this out and they insisted, straight faced, that this was really common. Which sounds unlikely, tbh, given most tests can't detect any sign, a week after fertilisation.