AF 7 months late..

AF is 7 months late, last period was 11/5/2014. All hpt are negative, but I haven't taken one in about 6 month. I've gained about 15lbs but don't have any symptoms or sign of pregnancy. I'm normally right on time with my period. I can't afford to go to the dr at all. Not sure what I should do. Does n e one know if I can find out if I'm pregnant?