I am almost absolutely certain my dates are a few days out, just coz with my first, they did a scan at 10 weeks and he was curled up in a wee ball, they did the length and said he was 10 weeks exactly but then he uncurled so they did the measurement again and said it was actually 10 weeks +4!
This time the scan was at 9 weeks and they said bean was exactly 9 weeks, but it was really fuzzy and all curled up, so i reckon it was longer but they didnt wait for it to uncurl, plus it was much smaller and stuff...
Jasper was born 2 days early (after a days labour, so i went into labour 3 days before my due date) and i have a feeling this one will be a week or so early. Just a hunch but thats what my heart is telling me. There is no way a scan would be 7 weeks out though, they grow massively in that time x