Spotting? But what kind??

Just went to the bathroom and noticed some pink in the paper. My period is 27 days late but i wasn’t worried because I have the arm implant so my period is irregular. I am sexually active but HES never finished inside. Is it implantation bleeding or am I starting my period??? Don’t know but I guess we’ll give it a while and see what happens. Put a panty liner on so I could document it better