Why?
Because my grandmother thinks of the potential pregnancy as if it's a real person and if the pregnancy turns out not to be true, she would mourn it as though she'd lost a real great-grandchild.
If I hadn't been sitting, I'd have fallen over on the floor.
This really doesn't improve my view of religious people. And while I know my grandmother is getting old and paranoid and forgetful, this is pure Catholic nonsense.