Duchess Kate Middleton stuns in surprise appearance at London Stadium

Duchess Kate Middleton joined Prince William and Prince Harry for her second surprise appearance of the week on Wednesday.

Just a day after her due date was announced, the Duchess stepped out in the chilly fall weather to help celebrate 150 young sports coaches graduating from Coach Core, a mentoring program founded by the royals themselves. The event was held outside at London Stadium, home to West Ham's football club, where she met with some of the soccer players and was handed jerseys for Charlotte and George. 

See more of the royal outing:

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Kate, William and Harry step out for Coach Core
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Kate, William and Harry step out for Coach Core
LONDON, ENGLAND - OCTOBER 18: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge smile up to the attendees following the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Avril Husband/West Ham United via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Catherine, Duchess of Cambridge smiles whilst attending the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Avril Husband/West Ham United via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Catherine, Duchess of Cambridge attending the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Avril Husband/West Ham United via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge attending the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Avril Husband/West Ham United via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge receive a baby football kit for their children from Mark Noble of West Ham United whilst attending the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Arfa Griffiths/West Ham United via Getty Images)
The Duchess of Cambridge, stands with some of the 150 Coach Core apprentices, as she attends their graduation ceremony at West Ham UnitedÕs London Stadium. (Photo by Dominic Lipinski/PA Images via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince Harry, Catherine, Duchess of Cambridge and Prince William Duke of Cambridge attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Samir Hussein/Samir Hussein/WireImage)
LONDON, ENGLAND - OCTOBER 18: Prince Harry, Catherine, Duchess of Cambridge and Prince William Duke of Cambridge attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Samir Hussein/Samir Hussein/WireImage)
Britain's Prince William, Duke of Cambridge and Britain's Catherine, Duchess of Cambridge share a light moment with West Ham United captain, Mark Noble (L) and West Ham United manager Slaven Bilic (2L) during their visit to attend the graduation ceremony of more than 150 Coach Core apprentices at London Stadium, in east London on October 18, 2017. / AFP PHOTO / POOL / Arthur Edwards (Photo credit should read ARTHUR EDWARDS/AFP/Getty Images)
The Duke and Duchess of Cambridge and Prince Harry at West Ham UnitedÕs London Stadium, as they attend the graduation ceremony for more than 150 Coach Core apprentices. (Photo by Dominic Lipinski/PA Images via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Catherine, Duchess of Cambridge and Prince William Duke of Cambridge attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Samir Hussein/Samir Hussein/WireImage)
LONDON, ENGLAND - OCTOBER 18: Catherine, Duchess of Cambridge and Prince William Duke of Cambridge attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Samir Hussein/Samir Hussein/WireImage)
Sir Keith Mills chairman of the Royal Foundation sits with the Duke and Duchess of Cambridge and Prince Harry at West Ham UnitedÕs London Stadium, as they attend the graduation ceremony for more than 150 Coach Core apprentices. (Photo by Dominic Lipinski/PA Images via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge greet a Coach Core member as they attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Chris Jackson/Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Chris Jackson/Getty Images)
The Duchess of Cambridge at West Ham UnitedÕs London Stadium, as she attends the graduation ceremony for more than 150 Coach Core apprentices. (Photo by Dominic Lipinski/PA Images via Getty Images)
LONDON, ENGLAND - OCTOBER 18: Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge attend the Coach Core graduation ceremony for more than 150 Coach Core apprentices at The London Stadium on October 18, 2017 in London, England. (Photo by Chris Jackson/Getty Images)
The Duke and Duchess of Cambridge and Prince Harry at West Ham UnitedÕs London Stadium, as they attend the graduation ceremony for more than 150 Coach Core apprentices. (Photo by Dominic Lipinski/PA Images via Getty Images)
The Duke and Duchess of Cambridge at West Ham UnitedÕs London Stadium, as they attend the graduation ceremony for more than 150 Coach Core apprentices. (Photo by Dominic Lipinski/PA Images via Getty Images)
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Kate sported a blue double-breasted blazer by designer Philosophy di Lorenzo, paired with a black turtleneck, black skinny jeans and heeled black booties. The blazer, which she also owns in red, reportedly retails for over $700.

The look is giving us major fall feels. 

Her unexpected outing comes just days after she made her baby bump debut in an elegant powder blue lace dress. Days later, she surprised at a royal event, dancing with Paddington the Bear at London's Paddington station. Suffering from hyperemesis gravidarum, or severe morning sickness, the Duchess was forced to pull out of a number of royal events over the past month. 

For more updates on her pregnancy, see the video above. 

See more of her impeccable royal style:

22 PHOTOS
Duchess Kate maternity style
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Duchess Kate maternity style
The Duchess wore her black pumps and carried a sparkly black clutch to complete her look.
The dress is a bit edgier than she typically chooses, but we loved it.
Just the tiniest hint of a bump! Kate is now 14 weeks pregnant.
The royal mom-to-be (round 2!) was glowing as she left the venue.
Kate attends the Action on Addiction Autum Gala in London on October 23, 2014, wearing a black Temperley London dress.
Kate, wearing a pale blue bespoke gown by Jenny Packham, arrives at the Natural History Museum on October 21, 2014.
The Duchess is the royal Patron of the Museum.
Kate dazzled on her first day back to royal duties since announcing her pregnancy.
The Duchess looked stunning in her floor length Jenny Packham gown.
She wore her hair down in bouncy curls with a delicate sparkly necklace.
Kate leaves the Natural History Museum.
The Duchess heads outside to present the awards of the evening.
Kate presents the Young Wildlife Photographer of the Year award to Carlos Perez Naval at the Natural History Museum.
Kate presents the Wildlife Photographer of the Year award to Michael Nichols at the Natural History Museum.
Kate leaves the Natural History Museum.
Prince William and Duchess Kate are seen as they welcome the President of Singapore Tony Tan Keng Yam at the Royal Garden Hotel on the morning of October 21, 2014. Kate is wearing a coat by Alexander McQueen and Jane Taylor hat. 
Kate's hair is pulled back in a low ponytail under her Jane Taylor hat. You can see the detail of the checked pattern of her Alexander McQueen coat.
The Duchess of Cambridge and Mary Tan depart the Royal Garden Hotel.
Kate smiles during the Horse Guards parade.
The duo prepare to meet the President of Singapore.
William and Kate laugh together during the Horse Guards Parade.
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