updated 01/23/2012 AT 4:00 PM ET
•originally published 01/23/2012 AT 4:10 PM ET
Like any expectant mom, Kristin Cavallari is already raving about her baby.
“We are so excited for this little bun in the oven :),” Cavallari, 25, Tweeted Monday.
The reality star and her Chicago Bears quarterback beau, 28, shared their happy news with PEOPLE exclusively on Sunday.
“We are thrilled to announce we are expecting our first child together,” they said. “It’s an amazing time in our life and we can’t wait to meet the new addition to our growing family.”
The couple first got engaged in April but split in July. Then in November, the pair reconciled. “This time it’s official,” Cavallari Tweeted. “Jay and I are engaged again :).”