In the preview for the Keeping Up With The Kardashians 10th Anniversary Special, the 36-year-old described how she was considering freezing her eggs after a fertility doctor told her that a pregnancy may be difficult.
But when she found out she was randomly pregnant, she recalls freaking out about the health implications.
"I remember calling [Kanye] and he thought a family member of mine had died, I was so hysterical. I thought my life was over, that I was pregnant and [it was going to be] so hard for me."
Later, the clip shows unaired footage of Kim suffering "debilitating" stomach pain while pregnant.
"At one point I thought I had a miscarriage, I was pretty certain about it," she reveals.
She flew home from Miami on Thanksgiving day to see her doctor, who told her: "there's no heartbeat. You had a miscarriage."
He urged to her to come in the next day for a private consultation, and miraculously, they discovered a heartbeat. "I was like 'oh my god!' It was an such an emotional Thanksgiving." At the time, her sister Kourtney was the only one who knew what was going on.
Though her pregnancies were difficult, thankfully Kim was able to deliver two healthy babies - North, 5, and Saint, 1 - and is reportedly currently expecting her third child via surrogate.