Lemme do that again.
expectANT mother.
Not expected mother.
An expectant mother is a woman who's pregnant and it waiting to have her baby, which will make her a mother (or add another child to her flock).
An expected mother is a woman who's already a mother and who has told you she'll be there are a particular time. So you're expecting her.
I hope most of you know this already.
Apparently, that giant amoung men, Don Roberts, on my local television station does *not* know the difference.