8 HPT all positive, blood test positive but now negative HPT!!!

Hey ladies I am freaking out! So I've had about 8 home pregnancy tests and they all pointed to positive! Went to the doctor and had a quantitative blood test and it was also positive. I'm meant to get my periods any day now, however yesterday I had brown spotty blood and it's not much but it's still there and is continuing. So I did another home pregnancy test with the Clear Blue digital and it says negative!!! Is this normal or I could be having a miscarriage? xxx