Plan B

my boyfriend and I had protected sex but as he was pulling out the condom stayed halfway inside me and I pulled it out but later felt something wet on my inner upper thigh, close to the vaginal entrance. I was terrified but was unable to get plan b until a day after. I experienced some bleeding and spotting a couple of days after taking the pill which I read was normal, but now my period is about 3 days late and I am absolutely terrified. is there a possibility I could be pregnant? am I overthinking this? please help