Confused on how to take the pill?

Hey, so I'm on the pill for about 4 months now but I am a bit confused. I got my period yesterday however I was on my second placebo pill. On the internet it says you take the pill for 21 days then you have a break for 7 days. But my period will go past the placebo week coz I started a bit later. So what do I do? Do I still take the normal pill when I'm on my period or not? Should I wait till my period finished then start taking the active pills?