miscarriage?

I have been having brown spotting since Friday (never even filled up a pad in 6 days) also had some rust (red/brown) colored bleeding. Got my hcg levels tested yesterday and were 315 for 5.3 weeks which is pretty low especially since I found out 2 weeks ago. Doing another test tomorrow but pretty sure I'm having a miscarriage. Has anyone had a miscarriage and had symptoms like this? Minor cramping, but hardly any blood. Passed a couple small things like this. This is the biggest.