Early scan, low hcg

meg

I'm so nervous about tomorrow I feel sick, I'm having an early scan due to low hcg, going by my last period I should be 8 weeks 4 days, but last week hcg was only 21, 4 days later it was 156, I have no idea what it is now, I know you can't see anything on a scan till its at least 1500 so I'm praying its been rising, I don't think I can cope with anymore bad news. I'm too scared to take any more pregnancy tests in case the line gets fainter