Kate Middelton flaunted her growing baby bump at her last official engagement at the Trooping the Colour ceremony in London Saturday.

The gorgeous Duchess of Cambridge reported to be going on maternity leave, dressed her pregnant stomach in a pale Alexander McQueen coat with a matching Jane Corbett hat. She wore her hair away from her face and accessorized the look with pearl earrings for the annual event, which celebrated the Queen's official birthday. 

Us Weekly reported that the mother-to-be rode in a horse and carriage alongside Prince Harry and Camilla, the Duchess of Cornwall, and glowed as she smiled and waved to the crowd. Middleton stayed warm with a blue blanket that covered her legs.

Queen Elizabeth II, whose birthday was actually on April 21, rode ahead with her cousin, the Duke of Kent. The 87-year-old wore a blue coat with a matching hat. Prince Philip was not in attendance, as he is still recovering in the hospital from abdominal surgery.

A source said that the Queen is in "good spirits" despite her husband's illness.

Meanwhile, Middleton is expected to relax and focus on final preparations for the baby due in July. 

Last Thursday, she christened the Royal Princess line in Southhampton, England. She stunned the crowd when she wore a printed dalmatian coat.

A few weeks ago, she was spotted furniture shopping, looking beautiful as ever. 

"She looked gorgeous," a source said. "Her hair was silky and from the front you would never even guess she was pregnant, but boy was there a bump! She looked marvelous."

Middleton or Prince William have yet to confirm the baby's gender, but the Duchess' uncle, Gary Goldsmith, said that he knows the perfect gift to get the baby. 

"I'm going to get exactly what I get for all my mates' babies," he recently told The Sun newspaper. "As a die-hard Chelsea fan, I always get the baby Chelsea shares. Then, when it's a bit older, I get it a full tiny Chelsea strip."

Tags: kate middleton pregnant Kate Middleton Baby Bump Alexander McQueen