Here's everything we know...
The Cambridge children make non stop news, from Princess Charlotte's signature sass and Prince George knowing he's different to Prince Louis' inability to social distance.
Rumours around another baby have been circulating the Duchess of Cambridge for years, with followers and fans constantly on baby watch. But could a new baby Cambridge actually be on the way soon?
Speculation started rising this year after reports that Prince William and Kate Middleton are considering a move to Windsor.
Kate also opened up about being 'very broody' recently, admitting during her current royal tour that she 'often comes home saying, "let's have another one".
This isn't the first speculation around a fourth Cambridge baby, with a body language expert predicting it last year.
Speaking to Express.co.uk, body language expert Judi James analysed Kate and Wills as they interacted with locals on their tour of South Wales.
'Their togetherness signals might suggest a new royal baby,' Judi explained, adding: 'Their other touches and tie signs would be more suggestive!'
Explaining how the couple has become more tactile, she continued: 'The body language of Kate and William here suggests lockdown might have suited both their relationship as a couple and as a royal team as they appear more relaxed and in-tune than ever before.
'The couple’s strong mirroring traits have always given clues of a like-minded relationship but here they seem happy to use many more tie-sign gestures than usual, keeping in communication with and enjoying one another’s company via glances, shared smiles and actual touches to allow us to glimpse more open affection and closeness.'
Kate Middleton addressed the reports of a fourth baby a few years back during an official visit to Bradford. When asked if she would like to add to the Cambridge family, the Duchess replied: 'I don't think William wants any more.'
Will there be a fourth baby Cambridge coming soon? Only time will tell.
