dates not adding up - please help !!

[MamaWingsIt]

I hope I am just being stupid, but here goes..

NHS due date calc says I should be 10wks 3 days. Had PV bleed last week, hospital offered a reassurance scan, sonographer told us I am 8wks 2days. Going off my last period date with the NHS date calc, I am wondering how it can be so 'out'? I hope I am just worrying unnecessarily, but worried that it isnt adding up?

TIA x

X

Well I had long cycles so there was a 2 week discrepancy between due date by LMP and scan dating for my eldest and 1-2 weeks with the others .

I found everything was based on every woman having a 28 day cycle. I KNEW my cycle was 34 days but this did not matter to them.

Agree. I knew exactly when I had sex so knew when I was pregnant (only had it over one weekend over three months as DH was away) they refused to believe it.

Did the sonographer say everything looked healthy?

Calculating from last period is inaccurate as it doesn't account for when you ovulate. Three women can start bleeding on the same day and then ovulate on days 10, 24 and 31 of their respective cycles. At a "12 week scan", one will be over 12 weeks, one between 10 and 11 and one only 9 weeks. Ish.

They can't take women's words for when they ovulate or when they had sex because there are myriad reason why they might be wittingly or unwittingly incorrect.

How long are your cycles?