HELP! LATE PERIOD!

So I had unprotected sex with my boyfriend but took the morning after pill the next morning. My period was due a few days before I took the pill and still hasn't come a week and a half later and I'm stressing so much that I can't sleep. I know stressing won't help it come any earlier but I can't face taking a pregnancy test and finding it comes back positive...is it just the pill making it late?