So confused? What does this mean?

So basically I am due on today however I haven't had any signs of my period, In fact I've been having signs of pregnancy. I'm not on anything to prevent a pregnancy. I took a test and it's got me all confused.... It came up with a faint line and then the faint line disappeared... Does this mean I'm pregnant but not enough hormones to detect it or is it just a faulty test? Has anyone else had this? Really need help here!! Please?? /: