The Wipeout host announced in March that she and husband Nick Lachey are expecting their first child together later this year. It has since been revealed that it will be a boy.
Vanessa confessed to People that, when she tweeted in March that she was hoping for a boy, she in fact already knew the gender of her child.
She went on to say that she would have assumed it was a girl if it had not been for doctors' confirmation otherwise.
"I already knew then [when she tweeted her hope for a boy] that it was a boy, so it was pretty easy for me to say I've always hoped for a boy first. [But] when it happened, I was over the moon and beyond excited," Vanessa explained.
However, she said: "I would swear to you that it's a girl because everything girly now is just clicking with me. When I see little girls, I melt; and when I see girly things, I can't wait to play with them or buy them."
Vanessa recently revealed that she is afraid her belly button will pop out as she becomes more pregnant.