When in early pregnancy and you're spotting during early pregnancy your blood discharge will be either black or brown in color and not red.
This is because the blood during spotting is not fresh and why it changes colors to black or brown.
The spotting will typically last from one to 2 days but some woman have reported it lasted 3 days.
It depends on the woman since everyone is different but the spotting shouldn't last longer than 3 days during early pregnancy.