Hello, i'm 27-28 days late for my period and 7 tests not pregnant had brown discharge 16-17 then nothing, have sore breasts, fatigue , cramping, help?

Missed period: physical or emotional changes in your life can affect your periods; recent stopping of BCP Too much stress,Diet change,athletic training,anxiety ,hormone levels, thyroid problem all can affect your periods---I would check with your GYN doctor for a better evaluation---possibly doing a B -HCG blood test for pregnancy---are your periods normally irregular?