How long could implantation bleeding last?

I’m unsure weather I’m getting an early period by 4 days or implantation bleeding (which started last night)

Ill post a pic with what I’m still getting ..

I’m still spotting light blood slightly.. so in questioning wether this is the start of my period which is strange for me to be early.

If I got a test today would something show if I am or would it be still early with me still spotting? X