Jen Arnold and Bill Klein of The Little Couple are beloved by TLC fans, who've watched as they adopted their two gorgeous kids, Will and Zoey.

But in their new book, Think Big: Overcoming Obstacles With Optimism, the duo, who both have skeletal dysplasia, recalls the moment they found out Jen was pregnant after struggling with fertility for years.

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“'I’m pregnant,' [Jen said in] complete and utter disbelief,” Bill remembers. "After going through two years of fertility treatments and surrogacy followed by miscarriages, this was unexpected, to say the least!”

The pair had already adopted their son Will from China at this point, and were in the process of adopting Zoey from India. But in a later doctor's appointment, they learned the pregnancy was nonviable.

Despite that crushing blow, the couple went on to a build a beautiful family for themselves. “Life has been this incredible and crazy and extraordinary road full of wonderful surprises,” Bill writes.

“I will see Jen’s beautiful smile and Will’s never-ending joy and Zoey enthusiastically hopping and skipping along and just think, ‘When did I win the Powerball of life?'”