Hello, I Am A Virgin But My Boyfriend & I

Hello,

I am a Virgin but my boyfriend & I didn't really have sex since he didn't penetrate or go in, but we did get naked & grinned on each other close to both of our parts but he isn't sure if he pre-cum while being close to each other is there any chance of me getting pregnant? Or what can be the percentage of being a change of that happening? But he is sure he didn't cum at all. I also wanted to know if it's better to buy a Plan B pill its to be sure or what is the recommendation to this scenario? Thank you.