Has it happened to anyone else?

I was supposed to start my period this week on the 24th but I started Friday didn't think nothing of it but when I started it was brown I usually bleed brown at the end never the beginning  my last day was yesterday but I only bled a faint kinda pinkish on Saturday morning then it went back to brown and my cycle usually last 5 to 6 days. Has this happened to anyone else or should I be concerned