Confused and heartbroken

The top one was from last Saturday and the bottom was Monday. I was so excited that after 8 months of ttc for #1 we got our BFP. But on Tuesday I started bleeding, first it was really dark brown sludgy almost, then it turned to dark red with a lot of tissue like particles. I went to get my blood work that day and when the nurse called me back yesterday all she said was it shows hcg levels 2.4 and that I was not pregnant. And the dr would call back to answer my questions, but never did. I don't get if that meant I had a chemical pregnancy or two false positives?? I'm so confused and I wish someone would've called me back to answer my questions..