Hello, so I had my period around the time I was supposed to but instead of it being the red heavy flow, it was a brown medium flow and has been going on for a week. I took plan B near the end of August and had knee surgery September 25 of 2015. Haven't been able to exercise due to knee surgery since my ACL surgery. I had sex before this brown period, it was protected sex and I am not on birth control but now considering it. I have been stressed about school so my stress levels have been very very high. This is the most stressed I've ever been in my life.