confused

Hi I am 13 days late of my period . I sometimes am nauseous and sometimes I can't stand certain foods like for example I love chicken and lately when I eat it I can't stand the smell and taste . I get very tired , I have cravings , and sometimes I get small cramps on my lower abdominal . suddenly lately I have stupid annoying headaches , heat flashes and very bad lower back pain . Am I pregnant ? I tried taking a pregnancy test but it was negative.