Spotting

Is it possible for spotting to just be a little speck or does it have to be more? My period is due Friday but I went to the loo last night and when I wiped I saw a bit of blood and all I’ve had since is discharge. Not sure if it’s because my period is close or it could be implantation? I’m 12dpo today sooo? I’ve also had headaches and my boobs have been soooo sore to the touch! But I don’t wanna get my hopes up cause I had the same last month and started my period! Not sure when to start thinking I’m pregnant or not? Also got no tests atm as didn’t think anything of it this month haha! Thank you x