You could definently still be pregnant.
Those test sometimes dont come back positive for a while. It just depends on the woman.

Go get a blood test
:)

A few days of spotting could be caused by cervical cysts. This is not harmful at all - simply blocked pores on the cervix. It might be worth getting checked for this if it continues. The most likely cause though is hormonal. You definately could be pregnant, so don't discount that possibility. Get another test in a week or so as it doesnt always show up straight away.