Period or implantation????

So I was late, but then I got my period. Started off the “first” day with slight bleeding but usual cramps, then the next day I was full blown bleeding red and changing my pad every hour cause of how heavy it was. Then the next day was medium, still super red blood, which is not really usual since I’m always heavy the first 2 days. Day 4 and 5 I have been using panty liners cause I’ve been basically bleeding a little bit of brown blood. I’m confused as to what this is cause every single cycle has been like clockwork and my flow has been the same.