The 32-year-old discovered she was expecting again just eight months after she welcomed her first baby, daughter Maxwell, in May last year.
Although the baby wasn't planned, she is delighted to be becoming a mother again and is more than happy to put her nuptials on ice.
"Apparently it was a part of god's plan for my life. I was extremely shocked... because I was going through a lot of hormonal changes, trying to get back to the old, vibrant Jessica," contactmusic.com quoted Simpson as saying.
"You know, it was kind of like a one-night stand. And it happened all over again," she added.