Over 6 weeks since normal period and just received 3 days of very light spotting.?

If the doc didn't see anything last week I doubt you are. You could just be having an "off" cycle. Just because it hasn't happened before means NOTHING. Until the beginning of last year I had a 28 day cycle SPOT ON. Never early, never late. Last year it changed. It ran anywhere from 25-31 days. No new diet, weight change, stress...nothing. It can happen. Wait a few more days I'm sure the spotting will get heavier. If it doesn't go back to the doc just to be sure...but I doubt it.