I lost a pill😩

I dropped one of my birth control pills earlier in my pack (i’m to the placebo pills now) when I lost it earlier I just started taking the next day. Well I had unprotected sex around that time and i’m afraid some of his precum might have been inside me bc he didn’t cum inside. I didn’t miss a pill or anything but now that i’m to the end of my pack I am 1 active pill short. It’s been a good week 1/2 - 2 weeks of my taking active pills since sex so I was still protected then right? My OB said I was fine but now that i’m on my placebo week and I still have no period i’m kinda stressing.