Confused about scan dates

[Mumtobe888]

Hello,

If you go for a scan and they say your baby is measuring at 12 weeks, does that actually your baby is 12 weeks size or are you actually 10 weeks pregnant? I don’t understand! I know everyone says two weeks get added on from your period but surely this is different from a scan?

12 week scan = Conceived 10 weeks ago, plus two weeks prior to that so it’s 12 weeks (for the uk anyway) and then the edd is set for 40 weeks in total.

I have heard some countries might measure it slightly different, hence why I added uk.

amp.flo.health/pregnancy/week-by-week/gestational-age

There’s gestational age (from lmp assuming it’s two weeks prior to conception, otherwise this won’t match lmp when you get to the scan. Mine is 10 days out due to late ovulation- ovulated on day 24). Then there’s fetal age- from conception. See the link above for more info.

Thank you both for your replies, so sorry if I’m being an idiot so an ultrasound adds the two weeks on that you’re not actually pregnant?