I have been on yasmin (21 pills) for a few months. I usually get my withdrawal bleed or "period" on the 3/4 pill-free day. this month, my withdrawal bleed started on the 3rd pill-free day as usual. On the 4th pill free day, i started a new pack as I'd like to switch the days of my period (I always get it on the weekend). Will this in any way influence the affectiveness of Yasmin ? am I still safe ? will there be any reprecussions ?