The 'Keeping Up With the Kardashians' star is currently in Las Vegas to have a post 33rd birthday bash with West and other family members, reported Us magazine.
"I was shaking the entire time. It was like an out of body experience," she said.
"Complete surprise. I truly had no idea. I don't think anyone there though -- they thought it was a surprise birthday party. Even everyone -- my sisters -- it was such a surprise. I'm marrying my best friend," she added.