Just coming back to update this, we went back to be re-measured today & it has moved up again.

It was 45cm (97th centile), now it is 46.1 - just above the 97th percentile.

So we are off to get an ultrasound - when I can find somewhere that can fit us in!

Dr was reassuring, she said if everything else is great (and it is) then it's probably nothing to worry about....I kind of freaked out anyway, but I'm a sook like that. I'm sure it will be fine