So I got my referral on Sat from my GP, it is for first trimester scan and BT.

GP says EDD is 28 March 2008.
FS says EDD is 4 April 2008.

Literature from GP says I can go for first trimester scan and BT (NT test) anywhere between 10 and 13 weeks. GP has written her EDD on the referral form which means I will be 12 weeks to the day when I go for the scan, instead of 11w2d.

Does this sound okay? Should I make the scan for a later date?