What Causes Light Vaginal Bleeding With Faintly Positive Pregnancy Test?

hi, i had a possible miscarriage in feb, i had spotting mid cycle after and then my period was late, hpt was faint, now im bleeding- not like normal period, lighter (not much though) and in no pain? do you think its possible mc or ectopic ( im little bit frightened) I just want to know whether to move on or not, my doc said last time to wait for bleeding to stop and do hpt, which came back negative in feb. what test results mean what?