14/08/2014 16:51 BST | Updated 22/05/2015 10:12 BST

Pregnant Katie Price: Fourth Pregnancy Is The Hardest

Pregnant Katie Price: I'm 11 stone with my hardest pregnancy yet

Katie Price has said her fourth pregnancy is her hardest yet and that she has gained more weight than with any of her other babies.

Looking blooming as she attended a book signing in Grimsby on Sunday, mum-of-three Katie chose to keep her latest bump under wraps in a figure-flattering grey T-shirt and patterned scarf.

The Daily Mail claims that the 35-year-old has said she is 'huge' compared to when she was expecting her other children, Harvey, 11, Junior, eight, and Princess, five.

"I'm the biggest I've been for all of my pregnancies. I'm 11st already, whereas I was not even 10-and-a-half full-term with the others," she said. (Here at Parentdish we'd quite like to be that 'huge'!)

Katie is also said to know the sex of her new baby, but is keeping that - and her due date - a secret.

Her pregnancy has seemingly been besieged with health niggles, with the model-turned-author tweeting about her back pain and tiredness in recent months.

The night before her book launch, Katie tweeted that she was being driven up to the event in her HORSEBOX, in which she had made a makeshift bed to travel in comfort.

"Lying in bed on my horse box with Junior and Harvey next to me asleep while being driven to Grimsby as have signing tom xx," she wrote.

Katie discovered she was pregnant with her fourth child shortly after marrying her third husband Kieran Hayler in January.

More on Parentdish: Weight gain in pregnancy