Anyone have heavy spotting with successful pregnancy?

I'm supposed to be 8 wks, started spotting on Sun with cramps, became heavier overnight. Went to Dr on Mon, they thought I'm either 6 wks or I'm having a miscarriage. They took blood and urine sample. I go back tomorrow (Wed) for results. Has anyone ever spotted heavily with a successful pregnancy? Could I really ovulate late and only be 6 wks?