Grabbing at straws here...

So I am AWAYS about a week or 2 later on my period than glow predicts. Today I bled some really dark blood - rustic brown color- and glow predicted that I would start my period in 3 days ... (I am 11dpo)

Could that be implantation bleeding or would it more than likely be AF arriving early?

I am never on time most times I’m late!