Implantation bleeding or period will come?

My period is 20 days late now. 4 days of having a not so dark brown discharge, sometimes reddish. Last month I had same exact scenario but only lasted for 4 days. I don't know if I'm pregrant or I'm just stressed. I worked last month and also january 10-11 hrs a day and now march it's 12 hrs a day for 2 weeks now. Idk if I just needed some rest for my period to flow. Thanks for the answer.