I don't think that's what she was talking about.
If you read the book Child Bride Elvis and Priscilla were having marital troubles early on.
Priscilla was mad at Elvis and in Child Bride it's alledged that she told people around her that she didn't want to have anymore children with Elvis.
IIRC One of the people she told this to was one of Elvis' secretaries but it never mentions her being pregnant again.
That's if you believe what Child Bride says.
I believe that's what LaurieT was referring to.