Suggest Treatment For Prolonged Bleeding

Hi! i am 20 years old and I had my menstruation since April 24 2011until now. I already consulted a doctor on may 10 and undergone transvaginal UTZ. the result in thickened endometrium, and she advice me to take althea pills but until now, the bleeding doesn't stop. what am I supposed to do next? can I take other antibleeding medications? I dont really want to go on D/C. are their other options? thanks!