HELP!!!!

So I missed two periods and decided that I better head to the doctors. The doctor decides to give me a blood pregnancy tests and tells me there is NO HCG present in my blood at all. Not even a range & that there would be one by now? However, my period still hasn’t come and my cm was very creamy and white. Recently my cm looked exactly like snot (just a tad bit of color to it too) what could this mean? I thought that was a sign of pregnancy?!??