Help hcg levels dropped

I'm 5 weeks according to glow I haven't had my first obgyn appointment yet I had to go to the er the 11th and when I found out I was pregnant my levels was 33 and then when I went to the er for a lil bleeding my levels have dropped to 20.5 he said I was high risk because of my thyroid problems and it can cause bleeding and even miscarriage and just low levels to start out with so what I was wanting to know is has anyone had their levels drop and come back up and have a healthy pregnancy and baby