Condom slipped off...help!

Okay, so I’ve been on birth control since Dec 2016, taking it almost perfectly. I take it as my backup birth control in case I run into problems with condoms...which I did.

On saturday, the condom slipped off inside of me after my bf came (aka it got inside of me but idk how much...he fingered me with it unknowingly being in me 😣). I was 9 days into my new pack when it happened (Sept 29). I had a breakthrough bleed from Sept 7-14 and I missed a pill the 6th but I took two the next day to catch up.

I’ve been paranoid since then because I’ve been cramping the past two days, but I know the chances are unlikely since i’ve been on point with taking my pills for more than 7 days. I just need advice/reassurance that i’m overreacting.

(I also considered Plan B but at this point I won’t get it until tomorrow which is the 3rd, so I don’t know if it’ll be worth it especially with being on birth control)