HELP! Should I be worried?

So I had sex tonight without a condom. I rarely do this, even though I am on the pill. I didn't take my pill on time this morning. I took it when I got home. He didn't cum inside me. I did some research online about  whether or not I should be worried and most things I read said if it's less than 24 hours after you were supposed to take it I should be fine. I don't really know how to get my hands on the plan b pill to just be safe. Should I relax? And stop worrying?