Confused!!

Andrea
Ok I need a little help. I had a miscarriage back in October. I had. My first period since my miscarriage in November. My period is supposed to start tomorrow and I'm having brown spotting. No cramps. My blobs are a little tender. Am I pregnant or am I getting ready to start my period. Please help me understand what's going on. I didn't have this happen last month when my period started.