Dating scan over a week out

[InsaneMummyOfThree]

So, I went for my dating scan today and I'm abit confused/gutted. It's 13+4 since my last period but they dated me at 12+2. I'm obviously fed up because they have effectively added 1 week and 2 days to my pregnancy now. I'm concerned though as I need to have elective c section due to previous births. Will this change later if baby starts measuring "large". That's also another issue as I'm being monitored for gestational diabetes due to being and I don't want them to think baby is "large" when actually it's just a week further on. Suppose I'm just hoping they will bring my due date forward again. Feeling fed up!!!!

Pregnancy is 38 weeks from ovulation. They add two weeks to take it to 40. How long are you cycles usually? Do you know When you ovulated?

Supposed to say due to bmi

The dating scan is more accurate than your last period date as everyone has different length cycles (ovulate at different times). I have long cycles (approx 35 days) so my dating scan has added a week on with both of my pregnancies, although I knew it would happen as I know I ovulate later than 'normal'. Also, implantation can occur at different times.
It's likely that your scan date is more accurate than your 'first day of last period' date.

When I was actively trying with my first I used ovulation sticks and ovulation occurred on cycle day 16 and cycles are normally 29-30 days so that would suggest average cycles if u know what I mean. Not sure of exact ovulation though. X

I've been told that I'm 3 weeks behind what I thought! Exactly the same re dates and scan. I'm concerned as my 1st baby was induced 3 weeks early as measuring small. I'm worried that my dates are correct and that if this baby is small they won't pick it up as they will think I'm in time if that makes sense. My useless midwife says I'll prob just go into labour 3 weeks early great - so helpful!

Scans aren't always accurate. I know exactly when I ovulate (to the minute - it bloody hurts me) and in my current pregnancy my dates were backed up exactly by scans at 6, 7 and 9 weeks. (I've had three miscarriages which is why so many scans). At the 11 week scan though it'd had a growth spurt though and they put me on two days. So all this 'foetuses develop at exactly the same rate for 12 weeks' is clearly bollocks, evidenced by their own scans!

Scans are definitely not always accurate. I was dated 2 days further than I know I am. This is an ivf baby - I can give them the exact time if needed! They just told me I probably have my dates wrong , erm no. I don't.

Likewise - scans aren't necessarily accurate.

My EDD based on scans has varied by up to 3 weeks either side of EDD based on ovulation, with radiographers and midwives condescendingly telling me my dates are probably wrong.

I know to within an hour or so when I ovulate because it hurts so much, and I also know down to the hour when we DTD that day. I also had a miscarriage 2 weeks before that. So no, my dates weren't wrong, the early scans just told me this foetus was developing more slowly than average.

Now at 33 weeks DS has caught up and overtaken the estimates (he's now measuring 3-4 weeks ahead in terms of size) and I'm being told my dates are wrong in the other direction - which is also wrong since I know we only DTD once in a remotely relevant timeframe!

I'd just wait til later on to see when the elCS gets booked for. Gestational diabetes/ macrosomia diagnoses will depend on more than the EDD being a week wrong.

Your cycles can change, they will test you for GD & react/monitor accordingly.

In the grand scheme of things, a week is nothing. Just enjoy the fact that you are 1) pregnant and 2) the 12 week scan didn't show any signs of any concern.