New pregnancy? Or old hormones?

Anne
Help! I had a miscarriage in 04/16/16. I have not had a period and tested negative on HPTs about a week after miscarriage. Starting on Sunday, it jsaw a faint positive and it has only gotten darker from there as you can see. My doctor did a blood test yesterday and numbers were only 178, so he said it is still left over from miscarriage. I just can't believe that since the line is getting darker! Could this be a new pregnancy? Or just residual hormones from miscarriage as my doctor thinks?