Today's BWOTD upon hearing, could make an American man panic!
"Can you knock me up at 7am tomorrow please"
'Knock me up' = Bang on my door
'Knock up' = Wake up
This does NOT mean please can you 'impregnate' me at 7am tomorrow! So no need to panic and scarper if a British woman ever says this to you ;-)
However just to confuse matters we do also use the phrase 'knocked up' to mean someone is pregnant!