help!! when can I start birth control?

Destiny
I just received the pill (Tri-Lo-Marzia) last night, after reading the package, it says I can only take it either on a Sunday after my period starts or on the day my period starts. My period ended three days ago, can I start taking it today or do I have to wait for my next period? I took the first one earlier today before I read the package (stupid me!)