Birth control + plan b


Hi.. so I've been on birth control for two months.. my boyfriend and I had unprotected sex and he cummed in me.. anyways, I take birth control as instructed and haven't missed a day(pill).. and I took plan b anyways cuz I was scared. I start my placebo pills tomorrow, and most people say that plan b throws off your period by like a week.. so idk what I should do??!? like do I take the placebos or do I go to my next pack of pills??