Hi thanks for your question.
last menstrual period of your girl friend was on September 28 and you had sex on October 23,There are very less chances that she will conceive from this sexual act.
She has taken emergency pill on 27th October that means after 72 hours of the sexual act,so that will not work,if she has conceived.
Best choice for you is go for pregnancy
test and if it comes positive ,go for abortion
consultation with physician is encouraged.