I'm Worried I'm Pregnant

My boyfriend and I had sex, we used protection (comdoms). I was off my birth control so we had to use a condom that night. We had sex 4 times that night. However the 4th time when he pulled out we panicked because the condom was not on his penis... we flipped the whole bed even though I kept saying to him I think it's inside me. He looked... and it was in fact inside of me. He spent an hour or so trying to get it out. He eventually did. But... I'm still worried I might be pregnant. I took the morning after pill.

I'm concerned, and honestly feel stupid.... like how could this have happened. My period is 4 days late now. I'm 19 and in college for nursing and in all honesty I'm just worried because I don't need any more chaos in my life.