The Duchess of Cambridge took part in her final engagement ahead of her maternity leave on Thursday - and royal watchers believe this indicates her due date.

Fans believe that Kate, 36, could give birth to her third child over the weekend of the April 28-29.

If they are correct the Duke and Duchess of Cambridge will be toasting not only their new arrival but also celebrating their seventh wedding anniversary .

The prediction is based on the Duchess' previous maternity leaves with Prince George and Princess Charlotte.

When pregnant with George in 2013, Kate began her maternity leave on June 16 having attended her final engagement in the form of Trooping of the Colour a day earlier.

Her firstborn arrived 38 days later on July 22, just over five weeks after her maternity leave began.

Similarly Princess Charlotte's arrival in 2015 followed almost exactly the same pattern, having been born just over five weeks after her mother's final engagement.

Kate and William visited the Stephen Lawrence Centre in London on 27 March and 37 days later Charlotte was born on May 2.

If the couple's third child follows the same pattern we can expect our newest member of the royal family on either April 28 or 29.

This morning a Kensington Palace spokesperson confirmed: 'Today's public engagements by the Duke and Duchess of Cambridge will be Her Royal Highness's last before starting her maternity leave.'