Am I experiencing Implantation? (no pic)

Aubs
How can I tell if I'm having implantation bleeding? 
Two nights ago I thought I was starting a period because when I wiped, there was red blood and some cm. Then nothing all day yesterday! And today when I wiped only some brownish cm and some "tissue". But that's it. Only light cramping after a bowel movement (which is when I've seen the color as well). 
I rarely have periods, but this is not like one I've ever had before. The first sight of blood would fit into the "6-12" day range for implantation... Has anyone else experienced this?