heya,
i dont think you are pregnant. the morning after pill is usually effective. i had a similar case i took the morning pill, and it delayed my period..i wouldnt worry too much, here's a tip though, if you have time google for "ovulation calender", its a priceless tool!, i'm forgetting the exact website but they have this calender that tells you when you are fertile, and when to expect your next period. you simply enter your days and it calculates your chances of getting pregnant on each day of the month. you can download a free trial version too! it really helped me understand my cycle more and how to calculate my fertile days to avoid disappointments. i'll try look up the website for you. but from what you've said chances of you being pregnant are slim.