The one-time reality star, who appeared in Matty J's season of The Bachelor this year, shared the news on Instagram.
"We are expecting! Our baby is 12 weeks old and it was wiggling his/her arms and legs, I was completely speechless looking at the screen for the very first time," she captioned a photo of her ultrasound. "It was dancing in my belly and it made me tear up!"
The rhythmic gymnast announced her engagement to partner Robert Rollington in August.