The Kardashians' worst kept secret is a secret no longer: Khloe Kardashian is pregnant!

On Wednesday (December 20), the reality star and fashion designer announced that she and boyfriend Tristan Thompson are expecting. The Keeping Up With the Kardashians star shared a photo of her belly on Instagram, writing she is "so thankful, excited, nervous, eager, overjoyed and scared all in one" about having her first child.

"My greatest dream realized," she wrote in the caption. "We are having a baby! I had been waiting and wondering but God had a plan all along. He knew what He was doing. I simply had to trust in Him and be patient."

"I still at times can't believe that our love created life," she continued. "Tristan, thank you for loving me the way that you do! Thank you for treating me like a Queen! Thank you for making me feel beautiful at all stages! Tristan, most of all, Thank you for making me a MOMMY!!! You have made this experience even more magical than I could have envisioned! I will never forget how wonderful you've been to me during this time!"

See Khloe's first official baby bump photo, below:

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