My period was suppose to start on sat 8/3 but so far no show

However i did have very light spotting from 7/27-7/30 light enough to not need a liner or tampon only a lil bit when wiping here and there. Normally i have a very regular flow and this app is usually 100%accurate with when it is coming. Could the spotting possibly of been a period even though it is nothing like my regular ones and almost a week early

P.s i did take a test on Mon 8/5 when it didn't show and test came back negative