It is of course possible that you are pregnant,the liquid that comes out of his penis (not ejaculation) called pre ejaculation can impregnate you,but seems unlikely that you are.
If you only did it real quickly and took the morning after pill according to instructions,then it is unlikely that you are pregnant.
BUT next time you should be much more careful.It sounds like your only young and so an unplanned pregnancy is the last thing you need at the moment.
STAY IN SCHOOL!!!