Implantation? Or period?

My period is 5 days late I have not cramped my period is NEVERRR late not sure what’s going on at first it was dark brown blood!!! I took a test on day three missed period picture below.!! I’m just not sure ladies!! Can’t you give me your best advice on what’s happening with my body? What can cause a period to be late. Is it normal for a period to start out brown that’s never happened to me before ever.!!