Threatened miscarriage

I went to the hospital because I've been spotting for days. I'm 5weeks 6 days. They did a sonogram and could not find anything. Not even a sac. My hcg was 2700 though. They said I may either have an ectopic pregnancy or I've miscarried. I have to wait 48 hours and retest. Has anyone dealt with not seeing anything in the Sono that early but still being pregnant? We are hoping for a miracle. It took almost a decade just to get a bfp.