To build HCG level in your body it usually takes about 45 days ... Take a test after 2 weeks of Ur missed period . Since it is delayed by 8 days , HCG level are just building up n so the faint line appears n it said to be positive as well as.
That's happened with me as well as... As I was not able to tolerate ,so took Urine test when my period delayed by 4 days ,n doctor too confirmed to b positive.