I am 22 years old. I have diabetes and am on insulin shots. I have been on insulin shots since June of this year. I also recently began metformin in July. I was on metformin prior to beginning insulin shots. I am on a low estrogen birth control. I am now a month late on my period. I continuously have taken a home pregnancy test each week, one at night and one in the morning. All of the tests have been negative. I have heard on several occasions that women with PCOS cannot get a positive on a home pregnancy test until they are pretty far along and that the only way they knew if they were pregnant was with either blood work or a sonogram. I have also heard that some blood test also show as negative. Is this true?