AF or IB?

Yesterday (9dpo) I had bright red blood when I wiped twice. Thinking AF arrived early, I used a light tampon. There was nothing but brown on the tampon. I used nothing last night and had no spotting or anything. Today I've had only very light brown spotting when I wipe.  I'm very confused. I didn't think IB could be bright red but why else would it just disappear?!?!