The 32-year-old reality star-turned-model, who is expecting her second child with Adam Horsley in November, revealed the news on Bank Holiday Monday in the most adorable way.
She is already mother to two-year-old Ariana, who featured in the photo that Thomas posted to share the news.
"This little Madam can't wait 2 be a big sister in Nov!" she wrote on the post on Twitter and Instagram.
The photo showed Thomas and Ariana looking at four scans of her baby, with a close up of the scan beneath.
Ariana, who sported a cute red bow in her hair, looked fascinating holding the scans and staring at the photos.
Hundreds of Thomas's 331k Twitter followings began rolling in with congratulation messages, which came as a surprise to Thomas.
"I'm an emotional wreck with all your lovely messages" she tweeted not long after announcing the news.
WOW! Thank you so much to all you wonderful people for the congrats. I'm an emotional wreck with all your lovely messages 😘😘😘— Imogen Thomas (@Imogen_Thomas) May 25, 2015
After posting the photo on Instagram too, she was again overwhelmed by the messages.
"Thank you so much everyone. Such lovely comments from you all. I can't wait to meet my little one....just before Christmas too," she posted on the photo after all the comments came in.
Speaking at the Mother and Baby Big Heart Awards in September last year, Thomas admitted she wanted another baby very soon:
"I'm so, so broody at the moment, it's crazy. My boyfriend's telling me to calm down, but I would love to have baby number two," she said.
It seems her wish has come true.
Congrats to the couple!