positive HPT negative at doctor's?

Maria
Hey guys 
So I have 4 positive home pregnancy tests I took at 10 dpo and I took another today and the line is just as faint. But I went to the doctor today and they tested my urine and said it was negative. Idk what to think. Doc said could be miscarriage. They told me to take a blood test but idk how long I should wait to take it. The lines on the tests are so faint I'm worried it's a miscarriage.