Will Plan B work for me or am I scared for nothing?

So... accidentally my boyfriend put it in without my consent, and he had pre-*** but he wasn't inside me but I believe I did have genital contact. He was rubbing against me. :$ If I take Plan-B in the next 24 hours...would it be okay? Will I be pregnant if I don't? Am I just stressing out too much? Please help me asap. And yes I know we should have used protection. You guys don't need to repeat that for me please. :$ Help asap!!