Congrats, Whitney Port! The 31-year-old revealed on Instagram Thursday that she's pregnant with her and husband Tim Rosenman's first child.

Next to a photo of her tiny baby bump, The Hills alum wrote, "Oh hey! Just standing by the window in my underwear, with a BABY in my belly!!!? 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!!!!"

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On her website, the mom-to-be added, "When two people love each other so much and the love becomes too great to fit inside both people, it spills over into a THIRD person. This is how I am going to explain where babies come from to the little baby that is now growing inside my belly because Timmy and I are PREGNANT!"

Whitney hinted that the news was unexpected, but shared, "I can’t wait to be a Mom."

The blonde beauty and her hubby got married in November 2015 after a two-year engagement. While planning her wedding, the reality star told Life & Style, “I won’t be having bridesmaids and he won’t be having groomsmen. I don’t even know if we’ll have a cake!”

Whitney — who ended up tying the knot in Palm Springs, CA — added at the time, “I want everyone to not feel like they have to wear anything or do anything! I’ll have a destination wedding with just under 200 guests. Not super small and intimate, not super massive. Right in the middle.”

News of her pregnancy comes one month after the fashionista's former co-star Lauren Conrad announced that she's also expecting baby No. 1.

Scroll through the gallery below to see what the rest of The Hills cast looks like now!