Implantation? Maybe TMI but no pics

I posted this elsewhere and nobody had any answers or thoughts so thought I would give it one last try here. Yesterday I went to er, after seeing doc for an asthma attack. ((He thought it might be a pulmonary embolism which it wasn't thankfully)) at the er they made me do a pee test at 1PM which was -. I am only roughly 6 dpo though so I didn't expect a + anyway. This morning I woke with some super light cm colored in the faintest pinkish brown. Its gone Now. Is the timing right for it to be implantation bleeding, even though it was just colored cm and not actually bleeding. Also my AF is not due to the 6th. Thank you for your time