Sorry - to add: so if I had cramps Friday the egg would not have been 'available' to sperm until Saturday?
Well you could have ovulated Friday or Saturday... and the egg can live for 12, possibly 24 hours. That's why it's best to have swimmers sitting in your tubes waiting for her royal highness queen of eggs to arrive and be fertilised. The egg is fertilised in the tube and then makes its way down to the uterus.

xoxo
M