Help!! Light bleeding!!

I'm 5w2d and woke up with what was pink spotting when I wiped and now is a little more red but still light. No cramping. After browsing the web, I decided to take one of my digital tests and it said "not pregnant." I didn't take a digital before, just a regular kind and it was positive. Could this mean a miscarriage? Or maybe my HCG levels are too low for a digital test? I'm planning to call the OB office when they open.