Pregnant Princess Beatrice in a polka dot midi dress at Wimbledon.

Princess Beatrice enjoyed a day at the Royal Box in Wimbledon on Thursday with her husband Edoardo Mapelli Mozzi and her aunt, Countess Sophie of Wessex, People reported (opens in new tab).Beatrice, who announced her pregnancy in May, wore a black polka dot She wore a gorgeous self-portrait white dress. (Kate Middleton visited Wimbledon last week in a navy polka-dot midi skirt (opens in new tab). The taffeta midi dress featured a square neck, puff sleeves, and a ruffled hem.

Beatrice customized the dress with a thin white belt, which she apparently placed over her pregnancy bump. She kept it simple with oversized black sunglasses and a delicate gold bracelet.

Incidentally, the self-portrait dress in question is still in stock and sells for $480. Hurry, before the royal effect takes hold and the stock runs out.

The royal family announced Beatrice's pregnancy in a social media post in May. The post read, "Her Royal Highness Princess Beatrice and Mr. Edoardo Mapelli Mozzi are very happy to announce that they are expecting a baby this fall," along with a photo of Beatrice and Mapelli Mozzi on their wedding day last July. 'We have informed the Queen and both families are delighted with the news. They will be younger siblings of Christopher Wolfe, whom Mapeli Mozzi shares with the former Dara Hoang.

Her sister Princess Eugenie also congratulated her on the news on her Instagram (opens in new tab). Sharing wedding photos and more candid snaps of the couple, she wrote: " Congratulations to Bebea and Ed on this news.