Brown discharge for 4 days still getting bfn

Tiffany

I have been getting brown discharge for the last 4 days. A little bit of spotting but mostly only when I wipe. Not sure what this is supposes to mean. I sometimes get it for 1 bathroom trip before my period starts but I've never gotten it this long. I've been testing but still getting the BFN. I've had slight cramping here and there but with my three angels I also had cramping like I was going to start my period. Is it possible I could be pregnant?