I missed AF yesterday!  I have been testing once daily.  All BFN.  I dug my Walmart cheapie out of the trash four hours later.  My very first evap line!  I know it means nothing but oh boy does it feel good to actually see a line where it is supposed to be, even if it is invalid.  I have been having dull cramps in all day today.  Strongly suspect AF is on her way soon.