The fitness fanatic, 29, announced she and her hubby Rio Ferdinand, 41, are having their first child together earlier this month.
Speaking to Mail Online, she says her life has already completely changed since becoming pregnant.
She says she already feels fatigued, but is still trying to stay fit and healthy.
She said: "I think being pregnant, it does change, you are a bit more tired at times but I try to stay active as it's good for my mind.
"We go for walks with the family, stuff like that, it doesn't always have to be crazy exercise just as long as you're moving more than you're sitting, you still feel good."
She also admitted that lockdown has been quite difficult.
During this time she has been homeschooling her three stepchildren.
She explained: "Up until the last month or so, I've found it [lockdown] a bit draining and difficult just with the homeschooling and keeping on top of everything."
Kate, who married Rio in a lavish Turkish wedding last year, is step-mum to Rio's kids: Lorenz, 13, Tate, 11, and Tia, nine.
Rio tragically lost his first wife and the children their mother, Rebecca Ellison, to breast cancer in 2015.
Rio and Kate are believed to have first met through friends in Dubai in 2017.
Since dating Rio, Kate left her reality television show behind, and is now a fitness influencer.
Sharing her workouts and fitness tips on YouTube, the mum-to-be lives a very healthy lifestyle.
It seemed inevitable that the couple would try for their first child after their marriage.
Kate had mentioned in interviews that they planned on expanding their family.
Back in January of this year she told Times Weekend Magazine that stepson Tate asked them when they would.
She explained: "He said: 'I love you Dad and Kate... and when's the baby?'
"They [her stepchildren] really do want us to have a baby, but we'll see."
She shared her pregnancy news to the world on June 19.
In view of her 1.3 million Instagram followers, she shared a touching video.
In it she and Rio divulge the big news to all three children - who scream and shout for joy.
What do you think of this story? Share your thoughts with us on our Facebook page @EntertainmentDailyFix.