Dark spotting on Birthcontrol pill

I've been on Orsythia, a combo pill for a little over a year and have never had this problem before. This started a week ago and I am now about to start my placebo pills but I have very dark brown mixed with blood spotting. I was thinking it may be my lining shedding because if how "fleshy" the discharge looks. I've been having it for a week now and was worried about what it could be. I haven't missed a pill. Right now I have the flu and just don't want to be stressed out about something else, can anyone tell me what it may be? thank you !