The 31-year-old glowed as she showed off her baby bump in a stunning bodycon emerald green dress, teamed with a gorgeous pale blue blazer.
Natasha and Ritchie before heading to the TV appearance
Fans were delighted when Natasha revealed on Twitter that she bought the dress from high street brand ASOS, but were quickly disappointed when she admitted that she had bought it years ago, and was recycling it for the appearance.
"Ah, look at us :)," she tweeted. "Love this dress too, was bought around 3 years ago on @ASOS #comfyas #vintage #recycle x".
She also revealed that the simple and elegant gold necklace she wore for the appearance was from jewellery brand Vamp London.
Natasha shared details of her outfit with fans on Twitter
Natasha and Ritchie, who found love when they reconnected on The Big Reunion, announced the pregnancy in early April, and Natasha took to Twitter to thank fans for their excited messages of support.
Thank you everyone for your kind messages and support. We are thrilled about the pregnancy xxx— Natasha Hamilton (@NatashaOfficial) April 1, 2014
While this will be Ritchie's first child, Natasha is already to mum to sons Josh, Harry and Alfie, from previous relationships, explaining that she didn't expect to get pregnant again.
"I had a lot of health issues last year with my ovaries and ended up in hospital," she said on ITV's Lorraine. "I was really poorly, I had a ruptured cyst and lots of pain and complications so the doctor spoke to me and said I may have to have my ovaries removed at some point which was quite a shock."
Natasha with Atomic Kitten bandmates Liz and Kerry