Early period or implantation bleeding?

I got what i thought was my period 6 days early this month, but it has been much lighter than my normal period. It has lasted about 4 days and and it has been bright red and brown. Ive had normal pms symptoms and with my first child i didnt have implantation bleeding. im wondering if anyone has experienced something like this? I have had quite a stressful month so it could be from that.