Could I possibly be pregnant? Plan B?

So last friday I needed a ride home and a friend offered, him and I have a long history so I told him I was not interested in anything more than a ride home, and he agreed.

I got in the car and he started getting touchy and ended kissing me. Then he started trying to take my bottoms off but I kept saying I didn't want to. He ended up saying "why do you even try pulling my hands away, it won't change anything". I was sad and yes I was almost crying. He ended up sliding my shorts to the side and rubbing his dick against my vagina. I do NOT think any penetration occurred. And he did not cum. I ended up pushing him away and crying saying I wanted to go home. And he started saying how sorry he was.

I know this counts as rape/sexual harrasment, whatever you want to call it but I feel fine mentally. I do not feel raped. I am simply worrying about the chances of me being pregnant and I know it's dumb since no penetration occurred and he did not ejaculate but I'm still worried. I'm sorry.

This was on friday and today's monday, the last day for me to take a Plan B pill and I was wondering if I should take one. Pills are kinda expensive to me so I dont know if I should.