Simpson told People magazine she couldn't confirm that prediction, but she and fiance Eric Johnson plan to undergo a test to determine the sex of the child.
"I think it's a girl," Simpson said at the debut of the new clothing line created by her and her sister, Ashlee. "But I don't know yet."
Johnson, an ex-NFL player, wasn't going along with his bride-to-be's prediction.
"I think it's a boy," he told People. "We're pretty much at a standstill there."