I started my period when I was 12. Have always been regular unless pregnant or on depo. Had my tubes clamped in May of 2006. Period was due around the 25th of July. The 21st I started spotting lasted about 3 days. Since my tubal my periods have been heavy(super tampon in a hour). Because of meds I'm on(remeron for depression, ativan for panic attacks and a combo blood pressure med/diuretic) the gyno ran a blood pregnancy test which came back negative a week ago. Still no period and now find out the diuretic could have caused a false negative. Does anyone have any experience with a pregnancy blood test coming back with the wrong results?