Pre-BFN symptoms

Callie • TTC #1! Married, 27:)
I've been having HORRIBLE back pain, I'm 3 days late and all BFN so far. I had some brown spotting slightly (only see when wipe for today only) and now nothing. I'm freaking out and just want to know if I'm pregnant or not!! Gonna test in the morning. Anyone else had any of these symptoms and come up with a BFP?