Jessica Simpson's second pregnancy came less than six months on the heels of the birth of her first child - news that was a complete surprise to the new mom!
"I don't know [how it happened]," Jessica told Ellen DeGeneres in an interview set to air Wednesday on "The Ellen DeGeneres Show." "Apparently protection was just thrown out the window!"
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Adding, "We were definitely extremely shocked."
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The "Fashion Star" judge, 32, said the second pregnancy has been the "complete opposite" of her relatively complication-free gestation with daughter Maxwell Drew.
"I felt amazing," she said, recalling the ease of her first pregnancy. "Like, I could do everything, eat everything. Do whatever I wanted. I had a lot of energy.
"This time around... I'm like, exhausted, eating Tums. That's my snack of choice!" she added.
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Jessica also said she's much more weight conscious this time, after learning how hard it is to shed baby weight.
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However, the fashion mogul said her fiancé, Eric Johnson, is supportive of her no matter how much she weighs.
"Apparently Eric still wanted me so... I can gain as much weight and I will have a husband-to-be that loves me!" she said.
As previously reported on AccessHollywood.com , news of Jessica's second pregnancy broke in late November 2012, and the bubbly blonde confirmed the happy news on Christmas Day.
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