I am 20 and sexually active with my boyfriend, but we use condoms and I have been on birth control for over a year and I take it regularly. Lately I start my period regularly on my second placebo pill, which would be today. But instead, today I am having a dark brown discharge. Last week I noticed that I had thick white discharge, more than usual. All symptoms have I read online point to me being pregnant, but we use protection and I'm on birth control. What does all this mean?