Another reason for having a false result on a blood
test is because 1) the
test was done too early, 2) you are pregnant but having a failed pregnancy, or 3) the hcg hormone does show up but is at a low level indicating no pregnancy.
In my case, I had a test done on the day my period was due. Levels came back below 5, which indicates no pregnancy. Three weeks later I was in the emergency room in dire pain from an ectopic pregnancy. So, while I technically failed the blood test, I was pregnant.