Whitney Port is expecting her first child with husband Tim Rosenman.

Former The Hills and The City star announced she's pregnant Thursday, February 9 on Instagram. 

"Oh hey! Just standing by the window in my underwear, with a BABY in my belly!!!" Port, 31, captioned a photo of herself wearing a nude lace thong and tied-up white T-shirt to show off her baby bump.

"DM me if you know what I'm supposed to do with this thing for how ever many years I'm supposed to be in charge. Check out my blog for a little letter from me & Timmy and for more behind the scenes of this crazy journey!!!! We are sooooo excited!!!! @colemoser."

Port married Rosenman, a producer, in Palm Springs, CA, in early November 2015, two years after getting engaged in November 2013. The couple met on the set of The City, which followed the premiere of The Hills series on MTV.

"It's such a great feeling!" the parents-to-be told Us Weekly at the time of their wedding.

"We finally get to stop saying fiance and be husband and wife! We really always knew we would end up together and now we can start a new amazing chapter in our lives. The wedding was everything we hoped it would be and will cherish the memories for the rest of our lives."

In Summer 2016, Port discussed the possibility of having children.

"We're both pretty ready!" Port gushed at the time. "I mean, not that you can ever be 100 percent fully ready because you have no idea what to expect!"

Port's pregnancy news comes right on the heels of former The Hills co-star Lauren Conrad announcing her first baby is on the way last month.

The Hills aired on MTV from May 2006 to July 2010. The City ran from December 2008 to July 2010.