Private ultrasound recommendation?

[carebear]

Hello,

Wondering if anyone can recommend somewhere I could get a private pregnancy scan at around 28wks? I'm hoping to take my 5yo on a specific date (a Thursday) so ideally would like to find somewhere easily accessible from ED either by car or public transport. None of the babybond places have appointment times that work and everywhere else I'm finding is on Harley St at 3-4 times the price!

Thanks in advance :)