Suggest Treatment For Irregular Menstrual Periods

I am 27 yrs old and a non muscular 105 lbs. I have had my period for over a week no and it is heavier than usual with a foul smell and is darker in color. As I have never had this before, I a concerned especially since I do not have insurance. I typically do not have a regular period, the time beteen them can range from one to three or even four months. What should I do?