What is going on??

Can anyone help me here? This past month was our first ttc. We got busy at least every other day after my period ended until my fertile window was over. My period is due in 8 days, but about 4 days ago I started spotting (dark brown). I thought this might be implantation bleeding, but it is still happening, so I'm thinking it's not that now. My Cycles have always been very regular and predictable, and I've never seen this brown discharge midcycle. I would consider it a light-medium production. It's actually starting to clear up now, but I just wanted some thoughts from you all! Also, I haven't had any cramping or discomfort down there. Could I still be prego, could I be having a miscarriage? Who knows. :) thanks!!