I know implantation bleeding is pretty uncommon… but

I know implantation bleeding is actually pretty uncommon and doesn’t happen for most people. But my period is still 6 days away and I’m only 9dpo. Do we think this could actually be implantation bleeding, or am I just getting my period early? I’m generally very regular, so I’m just caught super off guard by seeing this tonight. Also my boobs are starting to get way more sore than normal, but I had a negative frer test this morning.