What Causes Black Vaginal Discharge And Abdominal Discomfort Before Menstruation?

I m experiencing thick, black vaginal bleeding today but my period is 10 days early. I had bad cramps 2 days prior, mild abdominal discomfort yesterday which felt more gastrointestinal and no pain today. I ve always had a predictable menstural cycle... 28 days like clock work. The only time it s been different was when I was on the birth control Seasonique. I got pregnant with my son the first ovulation after I had stopped taking it and my cycle has never skipped a beat after giving birth. In the last year, I ve been diagnosed with Lupus and Fibromyalgia. I am also finally recovering from a 3+ month productive cough and sinus fullness. During those 3 months, I was treated with 14 days of Biaxin, 21 days of Augmentin, Z-Pack, 4 courses of predisone, 2 antibiotic injections, 2 steroid injections, a breathing treatment, a rescue inhaler and Dulera. I still currently take the Dulera and am on the last 2 days of prednisone. My primary and ENT ruled out pneumonia, did not feel it was related to the Lupus and diagnosed with with chronic bronchitis. I also regularly take Adderall for ADHD and recently switched from Suboxone strips to generic Subutex for opioid dependence. In the last few weeks, I ve been suffering from awful heartburn and have been taking Zantac.