Confused by dates given at dating scan.

[BluegrassLass]

To fill in the background, I had a BFP on 3 Jan, but then on 5 Jan I started with heavy bleeding. After several days, I POAS again and it came back negative, and a call to NHS pretty much confirmed I had a miscarriage.

I got another BFP on 5 Feb. So I just had my dating scan today for this pregnancy, and we were told that I am 12+5. Based on this, then the day I conceived was the last day of bleeding I had from the MC in early Jan. And I know we did not DTD that close to when I miscarried as I was a little sore.

How can I be this far along then? How accurate are the dating scans at this point in a pregnancy?

Sorry for your loss.

So you started to bleed 5th jan. And had a BFP 5th feb with no bleeding once the mc was complete. So the new pregnancy will be the result of you ovulating between those 2 dates. So as pg is dated from your last period, the start if your mc is standing in for that. So from 5th jan to 5th April is 3 months, so your date of 12+5 sounds pretty reasonable. Congratulations!

Sorry, the dating scans at this stage are pretty accurate.

You get pregnant when you ovulate. Usually around 2 weeks after your period, and if you are lucky 2 weeks after a mc. They date from start of last period, not day of conception.

It's just that based on when I'm pretty sure my OH and I DTD, I am confused how the baby could be measured at 12+5. I'm at least 10 days more advanced than I figured I would be.

Bonzo, you are correct that I did not have a period in between the miscarriage and my BFP on 5 Feb. But now that I've had a dating scan, they are no longer using LMP, but basing it on baby's measurements.

I mean, ultimately I'm not upset about this, and I'm not going to complain. I'm just confused!

Sorry for your previous loss.

From your scan today, conception was assumed to be on 23rd (or from sex up to a week before) the equivalent of LMP would be 9th jan which is just a few days after your loss. Basically you ovulated 20 rather that 14 days after your loss.

It is very hard being pregnant immediately after a loss, but you have had a reassuring scan after 12 weeks, so this does help hopefully. And it does appear to tie in with your dates! Hoe you can begin to enjoy this pregnancy with less worry soon.

Sorry meant to add that at around 12 weeks the scans are accurate to within +/- 3 days (some places give +/- 5 days)

So could be as late as 26th for conception date, but given when you got your BFP seems about accurate with dating given today.

You're quite right willitbe! I've now had a scan showing there is indeed a bun in my oven, and it helps alleviate worries. Before this scan, I kept saying "if there's anything in there" or "assuming things are progressing". Well now I know things are definitely progressing, and while there are no guarantees, I am now much less worried and can begin really enjoying this journey! :D