Implantation maybe?

Was supposed to start Saturday at earliest. Started spotting Thursday, kept spotting until yesterday, but not heavier than a panti liner needed maybe 2x in those days nothin today. Barely any cramping. Normally I have to have a heating pad, or take tylonel. What do you think. Headaches, nipples sore, slightly nauseous, more tired. Didn't have implantation with any other pregnancies, only 1 live birth. But got nexplanon out July 2nd. One period since. Then now this spotting. Mostly pink but some red.