Catherine, Duchess of Cambridge In Topshop - Inauguration Of Warner Bros Studios

Since becoming pregnant, Catherine, Duchess of Cambridge has managed to win us over with her maternity style – by ‘us’ I am very much including myself.

When the duchess arrived at the Inauguration Of Warner Bros. Studios Leavesden in Watford, England this morning, the mum-to-be – who was joined by Prince William and Prince Harry as they took the famous Harry Potter tour – wore a £38.00 dress from Topshop.

It instantly became such a hot commodity that it sold out in about an hour.

The polka-dot dress was styled with black suede shoes – obvs – a black Ralph Lauren cropped blazer and a small black box clutch.

Her hair was teased into gorgeous loose waves, plus she rocked a pair of pearl drop earrings.

Credit: FameFlynet & Getty