Advice please on possible implantation bleeding! Hopefully not TMI

Karen • Wife and Mum of 4 girls and one 👼 girl. Miscarriage May 2018. Rainbow baby boy due January 2020!
Been ttc for around 5ish months but this last month been we've really tried. My AF is supposed to be due 28th Sept (I have a long cycle) but when I wiped this morning I had light red on the tissue so put panty liner in. Walked to shops and back and had busy day so far but checked the liner and it just had a dark browny red patch in it. After wiping this afternoon it had red again with some little bits of brown in it so again put another liner in. I have had some mild cramping. Not sure if this is just AF turning up 11days early or its implantation bleeding??? Anyone had this or know? And how long did it last if you later found out you were pregnant? I think I had this before with my last child but didn't take much notice at the time of colour or how long it lasted etc so I can't remember! So confused...don't know whether to be excited or disappointed?!?! Advice anyone please?? Also I'm usually pretty heavy when AF turns up but this time it goes after a few wipes?!