Help with cycle

Okay so my cycle comes like clock work since having our 1st baby and then again after our second every month runs 20th to 26th for me this month on the 17th I started seeing light pink when I wiped this happen off and on for 9 days now ! My cycle still hasn't started I have taken 8 pregnancy test 3 of which had faint positives the other 5 negative again no cramps no cycle ? This has never happened, could I have ovulated late and that 9 days been implantation or something? Or could that odd spotting be my cycle this month