Is one day of brown spotting considered a period?

it wasnt enough to have to wear even a pantyliner....I am on the pill..same one for a few years and took it regularly without missing any. Always like clockwork and lasts for 3-4 days each month. What do you guys think? I have taken a test that said negative but I am still alittle concerned. I guess I will just wait till next week to see if I get it this month.