"I have always believed in second chances and my second baby I’ve been waiting so long for..." she added.
Her love story with Nate also has a cute hook - the pair previously dated in high school before rekindling their romance at the start of last year.
"My daughter Grace is going to be an amazing big sister and I’m so so grateful to be experiencing pregnancy + motherhood again with my love Nate x #pregnancyannouncement #babynumber2 #imexpecting"
Tracey, who is already mother to 10-year-old daughter Grace with a former partner, is best known for her stint on Married At First Sight's 2018 season where she was paired with Dean Wells.
The 37-year-old was a key player in one of that season's most explosive storylines when Dean "cheated" on her with co-wife Davina Rankin.
Dean and Tracey has since mended their friendship and he was one of the first people to wish her happiness after the announcement, writing, "Woohoo! So happy for you guys!"