What Causes Dark Brown Vaginal Discharge After Taking Alesse?

I started Alesse 28 for the first time this past month and today (Sunday) is the first day of the sugar pills.

Thursday morning my boyfriend and I fooled around and his pen** touched the opening of my vagi**. Thursday night I was late for my pill by 4 hours and started to have some cramps.

I then missed my pill Friday night and took two Saturday night. Saturday morning I started having dark brown discharge and major cramping today (Sunday).

Could I be pregnant or is this just part of the pill side effects?

Thanks