Is Prolonged Spotting A Sign Of Miscarriage?

My period was due on 6/1- On 6/3 I started spotting - very, very light bleeding. Not even enough to fill a pantyliner. Saturday morning I woke up to use the restroom and noticed discharge which included bloody mucus and tissue. I continued spotting very lightly until Tuesday 9which included pink and brown spotting). Is this a sign of miscarriage or implantantion bleeding.