Pill problems?

I began taking a new birth control pill 5 and a half months ago (Ortho-Cyclen). I have had a few irregular spottings over those months but only my period starting a few days early or a few days of spotting. Sunday and Monday mornings I was very nauseous after breakfast but thought it was just low blood sugar from working out. Then Thursday I began bleeding in the middle of my active pills cycle. I have been bleeding and cramping for 6 days now. I don't know if this is just a freak pill problem of breakthrough bleeding or if I had a miscarriage or something else? I take my pill same time daily and am married. NEVER miss pills or take them late. I even set a timer.