I'm stressing about possible pregnancy

Hi, so me and my boyfriend had sex like less that 24 hours ago. We did not use a condom, he did not finish inside me, but we are still stressing about it because he thinks that he kind of dragged some cum inside me, when he was touching me. So for us to stop stressing he bought me the morning after pill. I never took that before, I'm a little nervous. If I took that I should be fine, right? Besides the fact that there are many adverse reactions.

Thank you.