Implantation bleeding very close to AF? So confused!

Hi ladies! AF is due on Sunday, and I have had light brown and pink spotting since Tuesday- I'm going on day 4 of on and off spotting. I've never had spotting before my period, and it's only when I wipe-nothing comes on the pad. Can implantation be this close to AF and last this long? I don't have typical period symptoms either- it's usually super heavy with horrible cramps. Please help! I'm losing my mind!