Kate Middleton pregnant with the fourth baby?

BIRTHDAY BLUES Kate Middleton will not be with her hubby Prince William as she turns 37

2014: According to Hello, Middleton spent her first birthday as a mother at the Norfolk home she and William raised the young Prince in.

Odds that the Duchess of Cambridge will announce her pregnancy in 2019 have been slashed to 2/1, leading many royal fans to believe that an announcement is imminent.

Prince William knows what day it is. While her celebration plans now remain a secret, one thing is certain-her husband definitely didn't forget about the big day.

Catherine is thought to have celebrated her birthday with a low-key event at Kensington Palace on Wednesday.

When receiving the card, reporters captured him saying: "I did remember this morning, so I was OK".

William always seemingly picks gifts with sentimental value, marking the arrival their first child with a circular pendant inscribed with their son's full name, George Alexander Louis.

The Duchess of Cambridge is expected to mark the occasion with husband the Duke of Cambridge and their three children Prince George, Princess Charlotte and Prince Louis. Kate's daughter Princess Charlotte - who enjoys taking ballet lessons and attended a special viewing of The Nutcracker ballet before Christmas - would no doubt love to accompany her mother for the special engagement.

George will be celebrating his sixth birthday in July, while baby Louis, turns one on April 23.

And on Wednesday the palace confirmed William had become a Patron of their charity campaign, writing: "The Duke of Cambridge has today become Patron of London's Air Ambulance Charity #30yearssavinglives campaign - which aims to highlight the charity's vital work in delivering life-saving treatment across London, and raise support for the development of new facilities".

It's also likely the extended Cambridge family will join in on the celebrations.

Third, Prince William and Middleton's three children have at least two years gap.