Argh...I know this doesn't have much to do with the discussion at hand, but I took the morning after pill once...It was horrid, the first dose I took was fine, I had just eaten at my boyfriends house, but the next dose 12 hours later was me running out the door without eating...I didn't get very far on the bus (must have been about 10-15 mins after taking the pill) and I had to pull the bell and get out...I projectile vomited all over a feild trying to make it to the garbage bin. Not cool. I made my way home weak and weary and felt fine after some food and rest. But my experiance with the morning after pill was aweful. I hope all yours was better.
Anyways as for the question actually on hand, I doubt that you are pregnant. The morning after pill is not 100% affective, but it does work pretty well. I wouldn't stress about it, but in a week or two if you start to feel weird or are still concerned I would grab a home preg. Test and check it out.
Best of luck to you.
And remember to take food with the morning after pill!!
Kimmie