I Have Been On My Period For 14 Days, And

I have been on my period for 14 days, and the last 6 days I have changed my pads 2 an hour, and most of the time I pass a blood clot the size of a silver dollar or bigger. When i sit then stand up I bleed through my clothes almost immediately, and pass blood clots. I have a headache for the last three day, and have been dizzy and little light headed off and on for a week, I am 44 years old, I went to drs yesterday and he gave me estrogen pills for 2 days, a high dose, not helping making head ache worse.What should I do. thinking I should go to er?