Speculation Kate Middleton is pregnant again after she's not been seen for 58 days

Mystery is swirling around Kate Middleton after she hasn't been seen in public for nearly two months.

And now royal commentators are speculating the mother-of-three is expecting her fourth child.

The Duchess of Cambridge - who is already mum to Prince George, eight, Princess Charlotte, six, and Prince Louis, three - was last seen attending the Wimbledon Men's Singles Final and the Euro 2020 final on the same day on July 11.

But she hasn't been seen in public since.

Further questions were raised by royal fans when no new photos of the Cambridge children were shared by Catherine at the beginning of their school term, as she has done in previous years.

The longest the Duchess has previously gone without being spotted was 41 days last year, and the year before, 33 days.

While July and August are typically fallow periods in the royal calendar, royal expert Daniela Esler has pointed out that the last time the 39-year-old had a similarly lengthy time out of the spotlight was when she was suffering from Hyperemesis Gravidarum - which causes extreme morning sickness - while pregnant in 2017.

Kate's second and third pregnancies, with Charlotte and Louis, were announced in September.

So, if this is the case and there is another adorable Cambridge tot on the way, we may very well hear about it soon.