Hcg levels low

So 4 weeks ago i took 7 pregnancy test and they all came out positive.but very faint So i called my doctor and she sent me for blood work and my. Levels were a 7. So she sent me again 2 days later and they went up to a 9.i took another home test 2 weeks later and the lines were alot darker. After that she said wait 2 more weeks and ill send you for more blood work. I went yesterday day my levels were now at a 37. She has me coming in today for an ultrasound. I had very light spotting for 3 days 1 weeks ago.Could my baby be okay? Im freaking out a little because she said my levels are still low. And that i probably just am really early. Anyone go through anything like this?