Stupid dating question

[Singingforsanity]

Hi all

Feeling a bit thick here, hope you guys can help! At my 12 week scan a couple of weeks ago the midwife said I'd be '12 weeks on Saturday'. Fair enough. But I was checked over by the midwife on Monday, she asked how far on I was and I said 13 plus 2. She got her date worker-outer-wheel-thing out and said according to my date/her wheel I was 13 plus 3 🤔

Have I got the dating thing wrong? I assumed if you were 13 weeks on the Saturday you'd be 13 plus 1 on the Sunday etc? Or has her wheel failed her? My due date is a Saturday, so find it strange I'd change weeks on a Friday? Confused

I'd go buy what the dating scan said, I think that's more accurate, because they measure the baby and things like that

I've been told a number of dates so far as some go from the last day of your last period. Some first etc. I have 15th and 18th as due dates. ... I tell people it's 15th but vaguely say that week x

It's cos the time you ovulate every month can vary slightly. Dating scan is more accurate x