My 12 week scan is early...

[owltrousers]

I've just had my letter through for my 12 week scan appointment, except by my calculations I'll only be 11+3 on that date. Should I see if I can rebook it for a later date? I'm worried they might not be able to do all the screening I've chosen.

Between 11 and 13 weeks is fine. They'd have booked your scan date based on the dates you gave them, so this would be the next available appointment between 11 and 13 weeks so it'll be fine. If they scan you and you're earlier than planned they'll rebook another scan.

When I went to my 12week scan they found I was only 9 weeks so I was asked to come back again at 12weeks to my testing.

There's no harm in asking though if you are worried they won't be able to do it

Only issue is I haven't told work yet and the hospital we are booked in at is over 2 hours away by bus (we don't drive) so it would likely be most of the day off work. I don't want to have to repeat if possible although the idea of seeing baby twice is quite nice

You need to tell your manager as they have to allow you time off for maternity related appointments

It's completely normal to have your 12 weeks scan at 11+3, don't panic.