PLEASE HELP OR JUST ADVISE??

Mu
So this month my period was late by 4 days (not normal at all) I tested but negative. 
My period came on the 20th well I was spotting not a lot.....yesterday I bled like I would normally and now it has stopped like literally nothing if anything I had a slight pink tinge when I checked my cervix position. 
My period last the full 6-7 days every period and now this is the 1st time ever it's been a day?? 
Any advise what could be going on? Or someone experienced the same at all??