Scans

[Niftymum88]

Do dating scans go by your lmp or conception?

lmp was 8/12/25
ovulation test 21/12/25
first positive test 29/12/25
dating scan today says 5weeks 1day

by conception the dates right but by lmp I’m guessing it’s not ok

They go by the size of the baby. What’s wrong with the date?

I’m suppose to be 7 weeks tomorrow if you go by lmp but measuring 5weeks 1 day.

Are you periods regular? This is the problem with early scans, it’s going to cause you so much anxiety worrying something is wrong when it’s all likely absolutely fine

They add 2 extra weeks on from period/conception

They measure from lmp as a guide but that's not from when the baby was conceived so the measurements are right.

Have they booked you in for a repeat scan? What made you go for this scan?

It's just a guide. Mine always measured 2 weeks behind my dates. You go by the scan dates which gives you your due date.

It was suppose to be early reassurance scan n gender blood test. But said it’s an inconclusive scan

It doesn’t sound good unfortunately. I often try and take a best case scenario and use positive test date rather than LMP but because you got a positive so early I can’t shave off more than a few days. Say you got a positive at 7dpo (which you pretty much did anyway) you’d still be almost 7 weeks.
Was the scan internal? External scans this early aren’t as reliable so can sometimes account for not being able to see much.
I think all you can do is try and book another scan in a week or two. But ideally try and find an EPU that will see you. They will still likely make you wait a week or two from the first scan though to check there definitely hasn’t been any growth etc.

Yeah it was an internal scan.
it’s not looking hopeful I know.
im going to ring my midwife and see what she says next week

I hate to say it but private scans are a completely unregulated industry. Anyone can buy a sonography machine and set themselves up as offering a "reassurance scan". There's no guarantee that the person you saw had any training in how to estimate a due date, let alone in bedside manner and how to communicate their findings well.

You can definitely call your midwife for some reassurance but I can't imagine they'd do much other than encourage you to hang tight until 12wks. That's unless you had more reason to seek reassurance e.g bleeding?

I lost all my symptoms last week. I stopped feeling sick, I wasn’t as tired.
everyone said I was just lucky, but I had a gut feeling something was off.
i just feel so stupid.
cos we told people and our other kids knew.
now I’ve gotta break it to everyone that it might not be happening.
id been so careful, cut caffine, stopped vaping, ate well and took vitamins. Cut done on all my heavy exercise to simple ones.
but it just wasn’t meant to be I suppose