Very light spotting period for three weeks now, should i be concerned?

Depends if pregnant: Cause for concern is very dependent on whether you are or may be pregnant. If you are pregnant then spotty bleeding is not normal and you should see your doctor. If you are not pregnant then there are a variety of reasons you may be spotting. If you are still having periods then spotting can be due to hormone changes or fibroids. Usually this improves with time. See your doctor if it does not.