I accidentally let my boyfriend finish in me and I’m not protected?

I’m supposed to get my period in a few days, and I thought I was protected when it happened but I turned out to be on my last 7 days (the placebo pills). How likely am I to get pregnant? I will abort if this happens, but I’m nervous. Thankfully, I should find out this week. I’m 21 and he’s 24.
Update: I previously accidentally missed a pill or two during this month
Update 2: Well great news, I’m on my period, so dodged a bullet this time! I was mostly worried because I’m not perfect with taking them
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