dumb period

So for the past three months my period has been very consistent. Starts the 25 and ends the 30th I am not on any birth control since I have lost two IUDS got pregnant on the depo shot and I had the Nuva ring after I had my little man but it was horrible didn't like it . Well my period didn't come yesterday . I took a test 3 days ago it was negative . I took another one yesterday and still negative no clue why I wouldn't be getting it if I wasn't pregnant . I have no extra stress . Don't know what could possibly be delaying it .