Morning after pill?

Sorry I know this gets posted a lot but I looked it up and couldn't find anything matching my situation...I'm on my placebo week of my birth control pill and took my last real pill on Wednesday night. I should be starting my period in the morning. Bf didn't pull out quick enough, so I wait to see if I get my period or should I take the morning after pill tomorrow? And how will that affect my period with timing and actual period side effects? I'd LOVE some help here please!!!