Princess Eugenie announced her engagement to Jack Brooksbank on Monday, Jan. 22. (AP)

Princess Eugenie, who is counting down the days until she marries fiancé Jack Brooksbank, revealed that she is having "pre-wedding vibes."

On Thursday, the granddaughter of Queen Elizabeth II and the daughter of Prince Andrew and Sarah Ferguson, showed fans that she was getting excited about her upcoming nuptials.

The 28-year-old royal took to Instagram and shared a romantic, black-and-white portrait of herself taken for her 2016 Harper's Bazaar profile, and captioned it, "#tbt to some serious daydreaming going on here. "Pre-wedding vibes!"

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In a recent interview with British Vogue, where Eugenie posed with her sister Beatrice, the soon-to-be bride revealed that she wasn't worried about how things would go down on her big day.

“I’m not stressed at all,” she admitted. “It’s very nerve-wracking because you want it to be perfect, but then you realize that you’re going to be with the person you love forever and nothing else really matters."

And while the princess kept mum about wedding day details, she did tell Vogue that she is working on making her life plastic-free and plans to reflect that in her Oct. 12 nuptials.

"It’s been eye-opening,” she explained. “My whole house is anti-plastic now — and Jack and I want our wedding to be like that as well."

Eugenie will marry her groom in St. George's Chapel at Windsor Chapel where Prince Harry wed Meghan Markle in May.

According to Vanity Fair, Eugenie and Brooksbank have sent out 850 invitations, while 1,200 members of the public, selected by lottery, will also be welcomed onto the grounds to witness arrivals and the happy couple’s departure from the church.

A-list celebrities such as George and Amal Clooney, David and Victoria Beckham, Sir Elton John and Ellie Goulding are reportedly slated to attend the princess' big day.

Fox News' Janine Puhak contributed to this report.