implantation bleed question????

I've never had implantation bleed with my other   Pregnancys so I don't know a lot about it, but on Sunday evening I had just like two tiny tiny spots of blood when I used the restroom. I've tested both yesterday and today and both are bfn. Any ladies ever had such a small amount and it be from implantation? I'm still 3 days away from af, so I'm not sure. Any input would be appreciated!!