Kate Middleton and Prince William have been happily raising their three kids together. Although some spectators believe Prince George, Princess Charlotte, and Prince Louis will be the Duke and Duchess of Cambridge’s only children, royal fans suspect the 37-year-old is pregnant with her fourth baby.

The first week of September was a special time for Prince William and Kate Middleton. While Prince George has been attending Thomas’s Battersea, the escorted Princess Charlotte to her first day at the private school.

While the day should have been all about the royal children, fans couldn’t help but notice a change in Kate that sparked pregnancy rumors.

The Duchess of Cambridge was seen accompanying Charlotte to her first day of school when fans realized the 37-year-old was rocking a new hairstyle and color.

When Kate entered Thomas’s Battersea, alongside Prince William, Prince George and Princess Charlotte, she was sporting a shorter hair cut and a lighter highlights.

In the past, Kate has debuted new hairstyles during the early stages of her pregnancy to draw attention to her head rather than her growing baby bump.

Before announcing she was pregnant with Prince Louis, Kate appeared at Wimbledon with a shorter haircut. For her first pregnancy with Prince George, she sported a fringe haircut. 

However, with all three of her pregnancies, she was forced to share news of the royal babies earlier than expected because she suffered from a severe form of morning sickness.

Kate’s appearance on the first day of school sent royal fans into a frenzy on Twitter. Several individuals shared their thoughts on Kate’s possible pregnancy. “New hair cut - is Kate pregnant again????? She always sports a new hairstyle when she’s pregnant,” one fan wrote.

“Kate changed her hair again, I’m pretty sure she’s pregnant,” another fan added.

The palace has not acknowledged rumors suggesting Kate is pregnant with her fourth child.

Kate Middleton Kate Middleton arrives to launch a new national support line at the charity Family Action on Jan. 22, 2019 in Lewisham, England.  Photo: Getty Images/Adrian Dennis