i think your gf just wanted to scare u.
if you do it 2-3 days after period.. you have least chance to get
your gf pregnant... because there is no egg.. (eventhough the
sperms can stay for 3 days)
normally, it's 14-16th days after period when egg is ready...
calculating based on the durability of your sperms.. you should not
do it after 10th days after your gf's period...
this is common sense...
better don't have sex if you and your gf don't know all these
things...
