With baby number two on the way, the 32-year-old flaunted her maternity curves – in a skin-tight, animal-print dress – during an appearance on Tuesday’s “The Tonight Show With Jay Leno,” and was her typical, candid self.

Simpson – who confirmed her pregnancy in December – said she was “extremely shocked” to learn she was expecting so soon after giving birth to her 8-month-old daughter, Maxwell. She then went on to, gulp, detail the baby’s conception. “I was going through a lot of hormonal changes, trying to get back to the old vibrant Jessica and it was kind of like a one-night stand,” she said. “And it happened all over again!”

As for the “Fashion Star” mentor’s plans to marry fiancé Eric Johnson, who Simpson described as “is very proud of himself” for getting her pregnant, she says the big day is again on hold. "We've had two different wedding dates, but he keeps knocking me up! We're doing it very backwards." She added that the next time they set a date, "I'll just keep my legs crossed."

Simpson – who is due in the summer – said that this pregnancy is different. In addition to morning sickness (“I’ve been puking!”), the Weight Watchers spokesperson is "trying" to be healthier. “The last time I kind of ate everything in sight,” said Simpson, who dropped 50 pounds after giving birth to Maxwell in May. “I didn't really make any healthy, good decisions."

However, she is proud of her recent decision to tweet a photo of herself showing off her pregnant belly in a bikini. “I felt really hot and I thought I deserved a Kim Kardashian moment,” she laughed, referring to the E! reality star who is known for her bikini self-portraits (though none since she announced her own pregnancy). “My bump looks cute – I want to share that.”

Simpson also shared a few details about the new sitcom, loosely based on her life, that she will be starring in for NBC. “I will be playing myself, which is pretty easy,” she said of the untitled project in which actors will play the roles of Johnson as Simpson’s father/ manager, Joe. “There are lots of things that happen in my life that it’s like: People have to know about this,” she said. “All the embarrassing things that happen behind closed doors that I always wish were filmed. I’m not sure if it’s because I’ve done reality [TV] before. I’m always like, ‘God that would be such a great moment for TV.’”

In other words, 30 minutes of Chicken of the Sea moments. Bring it on!