Bek-
When I had an early ultrasound, it said the embryo was in fact 5 days OLDER than what I thought my dates were. According to my dates, Nina was due on the 20th September (the u/s said 15th...)

Then at my 19week scan the date moved again!! I think when they do the measurements, they compare the results with the 'average' growth expectancy and work the due date out on that.

I happen to know the EXACT date my daughter was conceived, and even with these u/s dates, Nina was born smack bang on the 20th September!!!

Don't fret, the date will probably change again as your babies growth pattern emerges. Babies are very rarely born exactly on the due date anyway! Sometimes they like to surprise us, sometimes they like to test our stamina by arriving two weeks late!!

Hang in there and good luck.

Julesy