AF or implantation bleeding ?!!! Help !

Angelica • Trying for 12 months now . Baby # 1
So.. My AF was due 21th .. I m 3rd day late.. Hour ago I ve noticed light pink and then brown spotting.. Only on the paper when I wiped.. I don't know if it s coming period or maybe implantation bleeding ... I don't have any symptoms of AF.. Not pain no sore bubs.. What do you think ? Any advices ??