4 days late but bfn!!

I am 4 days late for AF and going to do a first response test in a few hours. I have done the Wal-Mart .88 test and showed bfn. I have had cramping on and off now for about a week with clear discharge. If i take the first response test and it says bfn does that pretty much blow my chances for this month of being pregnant? I am anxious to find out or not but yet nervous it will say bfn.