A few weeks ago I took Plan B (about a day and half after the incident). My period was expected to arrive on the 24th of this month, but it is now the 29th and my period is no where in sight. When I went to the bathroom today, I noticed a heavily thick and clearish brown discharge of some sort. I was playing around with it to get a feel for what it is, and it feels extremely thick and difficult to break with just two fingers. Is it a sign that I may be pregnant, or that my period is coming? Also, what are the chances of me being pregnant if I took Plan B within 72 hours?

Thank you!