the last time i ever had sex was december 26th and it WAS PROTECTED. i got my actual full blown period january 15th. i got sick one day last week and decided to take a pregnancy test, within the time frame my .88 cent test showed up negative, the next day i look at the same test and it was positive, i decided to take two more tests of a different brand and they were negative...thats so weird to me can someone help???