My period is late. I *did* have unprotected sex for like 20 seconds last week, however I was not ovulating and he did not cum in me. My periods are fairly regular. Before my last period however I took plan b and that caused it to be late by two days. Can plan b effect more than one cycle? Or is this something else? I've been experiencing cramping and all of my usual symptoms, the same CM I get before my period, just no period yet.