What does 6 +2 mean exactly?

[Blinddate]

I know it means 6 weeks and 2 days but does it mean exactly 6 weeks 2 days since the sex that resulted in the pregnancy?! Like, actual conception date?
Thanks

[Kayzr]

No it means 6 weeks and 2 days since the start of your last period.

[Blinddate]

But she knew the date of my last period and this figure is different. It was dating from a scan if that makes a difference

[KatAndKit]

Pregnancy dating is based on you having a 28 day cycle with ovulation on day 14. If your cycle is longer or shorter than this then the dates will not tally up. Doesn't mean anything is wrong though.

Say you have a 32 day cycle and the scan says 6+2. Actually, it's probably 7 weeks since your last period but the scan doesn't know that.
Scanning looks at the size of the baby to work out when conception was and then adds 14 days.

So long as there is not a massive difference don't worry.

[Blinddate]

Ok thanks!