Confused

I had my blood hcg test on 13th night 10pm and it was 4255. Did another test today 19th at 2pm it came 12259. Is this normal? According to my LMP I m 7 weeks and 2 days but the doc cannot see any embryo or sac in my scan. I went to a radiologist today and he also told me it was an irregular shaped sac and I might only be 6 weeks 2 days.

Radiologist and doc thinks it might end in a miscarriage. Is there any hope? I really want this baby.. has there been any success stories.d