Fox, who gave birth to her son Noah (with husband Brian Austin Green) September 7, told Jay Leno she "had pretty bad morning sickness" leading up to the delivery, drawing parallels between she and a cinematic favorite.
"It was so bad for me, actually, I was convinced that I was, like, maybe birthing a vampire baby like the one from Twilight," said the Transformers beauty, 26. "You know what happens to Bella, where she's in cold sweats all the time?
"I felt like that was happening because I had no vitamins and nutrients and I was just nauseous."
Watch the video on RadarOnline.com
Despite the setbacks, Megan summed hers' up as "a perfect pregnancy."
Megan's new movie This Is 40 hits theaters on Friday.