The Great Kate Wait is turning into the Overdue Duchess. Many reports suggested that Kate Middleton's due date was Saturday, but Whitehall sources told The Telegraph that the due date was actually Thursday, April 23.

Most likely, the staff at the private maternity ward at St Mary's Hospital, Paddington, where the duchess will give birth, has already scanned her to make sure the baby is doing fine. Middleton could stay pregnant for another two weeks, or she could be induced sooner if she is feeling uncomfortable.

A source whose children were born at the Lindo Wing told The Telegraph: "The doctors don't normally wait for more than a week. They will probably already have been in touch with Kate and talked about which day which suit her best to go in and be induced if the baby doesn't arrive in the next couple of days."

Prince George was born three days past his due date, but anyone who bet money on an early birth for baby number two has already kissed their cash good-bye.

The biggest bet so far on the royal baby - £10,000 - was taken by Ladbrokes. If the customer is right, he could win £15,000. He told The Telegraph he normally sticks to horse racing and football, and that this is his first bet on the royal family. "I'm not really bothered by the Royals, but I'd just had a big win and my missus reckons it's a girl, so that's a good enough reason for me," the man from Manchester told The Telegraph.

The 4/1 favorite for day of birth as installed by Ladbrokes is now Wednesday, the duke and duchess's fourth wedding anniversary.