Red Blood early AF or Implantation Bleeding?

Sarah
My AF glow said 25 Tuesday and other APp said this coming 22saturday. And it's 20 now and when I wiped I have red Blood it's not heavy flow. And I have cramping now. 
​I took PT earlier morning and got Faint positive. It's too early for AF to come. What is this? 
​The pic is  faint line yesterday.