Please help!

so I took MAP about it 10 days ago and my actual period is supposed to be due at the end of this week. I'm not sure whether this is my actual period starting early or is it just side effect of the MAP? (I took MAP before and had bleeding 5 days after). my period is normally very short, intense for 2 days then very light for another say or two. I want to start with the monthly contraceptive pills (it says must be taken on the first day of my period) but I'm not sure whether this is it or not. can someone please give some advice? thanks