The television presenter, who is expecting a baby boy with husband Nick Lachey, confessed that she lives in fear of her belly button sticking out as she grows more pregnant.
"I thought, 'Oh, I wouldn't mind if it popped because then it would be like the turkey's done, right?' And it's cute," Vanessa told Bethenny Frankel on her talk show.
"But my stylist was like, 'You don't want that to pop. That's like having a third nipple'."
Vanessa went on to say that she now does everything she can to keep her belly button from popping.
"Every time I sneeze, I hold my belly button in," she admitted. "For some reason, I think I'm going to sneeze it out."
Vanessa recently revealed that Nick has begun "nesting", adding that the two have been working together in preparation for parenthood.
The couple's son is due in September.