The Coronation Street actress, 31, took to Twitter on Saturday night (11 October) as she enjoyed a slouchy night at home watching The X Factor.
And it seems Catherine had to dig deep in her wardrobe to find a pair of comfortable bottoms to fit her changing shape!
She posted a picture of herself make-up free, with her blonde hair tousled on top of her head in a ponytail. Along with a red long-sleeved T-shirt, the soap star can be seen wearing a pair of loose-fitting tartan pyjama pants - with drawstring waist for that growing baby bump.
The usually super-glamorous star wrote: "The Xmas pants are out!! Feel like Phoebe from Friends in 'Santa maternity trousers' #mindthebump."
The day before, she had told her fans she had a "very wriggly bambino today #lovestokickmummy".
She and her boyfriend Tom Pitfield announced their pregnancy in August, saying they were "thrilled".
Catherine, who plays Eva Price in the ITV soap, told her Twitter followers: "Delighted to tell you all that @TP_PTfitness and I are expecting a bambino! Beyond thrilled :-)."
The cute couple then revealed they had got engaged just one week later!
She is thought to be due in February.
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