Can Pill Cause Heavy Vaginal Bleeding During Period?

I had the Depo Provera shot in November 2010, and have now started my period. It was one week of spotting sort of. I have a trip planned for this weekend, of which I DO NOT want to be having my period, so started the pill to try and stop it yesterday.. but am bleeding more now.Has the pill made my period come on heavier or will the pill stop it if I carry on taking it?I know this may mess up my cycle, but I REALLY don't NEED my period this weekend and want to try ANYTHING to stop it.What can i do to stop my period quickly?