How Should Irregular And Early Arriving Periods Be Treated?

I am expiriencing an irregular period for the last three to four months my periond keeps coming earlier and earlier each month like a durastic change this month i started the 2nd had it for 4-5dys then i just started the 26th two times in one month, i took a prego test last month it was negative i've been off of birth control for over 2yrs now i have no medical insurance. i have no idea what is going on