12dpo

Bri • Newly married and trying to conceive our first baby! My husband and I have been together for 11 years and are excited to see where life takes us!
Hi ladies!! 
Is 12dpo too late for implantation bleeding?
I wiped and had some like pink mixed with a little EWCM. I've had some cramping prior and sore boobs off and on. I've taken multiple pregnancy tests- all negative! 
I do not know when AF is due.. 😁 my last period was 12/6. I had a positive opk on 1/16 using clear blue digital..  (Not sure if I skipped a period or ovulated super late) 
I've never had pink discharge before AF it's always brown.. But I guess there is a first time for everything. 
I have a doctor appt on 2/2 to see what's going on. 
Just curious on y'alls thoughts? Late implantation or is AF finally making her way back?
Thanks!!!!