There are a number of clues known to experts that could indicate Kate is pregnant.
These range from her schedule, her clothing and even her hair.
Royal expert Aranzazu Santos López told The Hits: “I have two clues that make me think Kate is pregnant.
“What are those clues? Look at these recent images of the return to school day. Look at Kate’s hair. It has a different air.”
The expert was referring to a moment in September 2019 when Kate and William took Charlotte for her first day of school.
“Kate’s new shade is very much a lightened balayage base, with a dark blonde overlay,” commented hair colour expert, Scott Cornwall.
“It’s actually very simple to achieve; the hair has balayage panels, lightened out around the front and throughout.
“The balayage would have been achieved using a bleach or hair lightener.
“After this lightening, a tone-on-tone or demi permanent colourant is applied throughout, in a deep blonde base.”
William’s smile could be a key sign Kate is expecting.
Judi told Express.co.uk: “William would be a very poor poked player as his facial expressions are often a give-away, especially when it comes to any good news.
“Unlike his dad he might manage to mask negatives like anger or frustration, but watch out for a lot of suppressed smiling if/when he is sitting on a fourth baby secret.
“Trying to suppress a smile leads to a softened eye expression and narrowing and crinkling of the eyes, plus a pushing together of the lips, but the smile breaking out at the corners.”