My period is dragging on

Teresa

I started my birth control like almost 4 weeks ago now and it caused me to miss my period. Then a week after I missed my period, I got brown discharge that turned eventually turned into my period but I feel like it's dragging on for too long now( it's been 5 days now. My period is usually just 4 days or 3 days) and I'm on the sugar pills now of my birth control. Is this normal ?