What Causes An Unusual Smell With Bleeding When Missing A Pill?

i have been using my birthcontrol for almost three months now, and i seem to miss just one day usually the second week of the new packet. My pills are good for 21 days and no pills for non active days, every time i seem to miss the one pill the next day i end up having a stange period with unusual smell and once i'm done i seem to have like an orangy color and smell weird.... and once i begin my unactive days i starts my peiod again??? Do i need stronger BC pills