Bleeding

I was told i was about six weeks pregnant  basing off my last period. I started spotting on wenesday and had been till yesterday started bleeding heavy went in to the ER had an ultrasound they could not see anything. :( then my blood work came back and the doc told me my HCG level was low at 40 he stated i can possibly be misscaring. I am still bleeding now no pain just tinny blood clots. Any advice