12-13 DPO- Brown Blood, why is this??

Hi ladies

I’m 12-13 DPO today and for the last few days I have been having brown spotting my AF is due tomorrow.. I have very sore boobs today & a bit dizzy at times also extremely bloated. I took a pregnancy test 2 days ago which was negative :( an I out this month ? I had a miscarriage in December & I’m wondering as this is my second cycle post d&c; could it be leftover blood from that?! I’ve never spotted before a period ever before.. I’m wondering is there a chance I could still be pregnant?