"I just got the blood test back, and I am pregnant," she said in a preview for a future episode of the show.
Now, Kim, 34, is opening up about the good news to Glamour magazine.
“We are so beyond excited," she told the magazine.
“I’m a completely different person,” she continued about motherhood and her growing family. "If it all went away, and I was just a mom, I would love my life.“
Kim also opened up about her past fertility struggles, which she detailed on the show.
“I didn’t know that I was going to be so open with [my fertility challenges]. But meeting people at my fertility doctor’s office who are going through the same things I’m going through, I thought, Why not share my story? It’s been really emotional," she added.
In addition to Kim, her mother Kris Jenner also reacted to Sunday's big news.
"Congratulations!!!!!!!!!! Can't wait to meet your new little love bug!!!!! Sooooo happy for you guys!!!!!!!!!! ?????????? #blessed #love #family #youaresobeautifulpregnant," she posted on Instagram.