Nervous as FUCK.

I have been using the pull out method with my boyfriend lately. I had unprotected sex and used withdrawal method about 5 days ago, but we took a morning after pill just in case. Today, I went to the restroom and found a brown liquid spotting. It has no smell and is very light, only when I put the finger in. Could this be a sign of early pregnancy or an early period? Last time I took the plan b pill I got my period about two weeks early. What is this stuff?