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!"
Adding, "We were definitely extremely shocked."
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.
Jessica also said she's much more weight conscious this time, after learning how hard it is to shed baby weight.
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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