Told I was miscarrying on 7/20 ( I haven’t passed anything or have had blood clots, very different from my first miscarriage) SOS

Hi everyone, if anyone could give me some advice or insight I would very much appreciate it. On 7/20 I was told I was having a miscarriage because of my HCG levels falling, they sent me back on the 21st to get my HCG numbers and it was 337. I started bleeding on the 18th (not a whole lot though.) I went to my appointment on the 20th, and they did an ultrasound and saw nothing (the doctor said it was too early). Since the 18th I haven’t passed anything, or have had any blood clots, or cramping or pain. With my first miscarriage I had all of that within one day of my bleeding I passed everything (naturally). Today is the 28th and My bleeding has completely stopped. My doctor wants me to get my HCG levels drawn again tomorrow or Friday (that’s what the nurse told me last week) but I’m really concerned, I don’t know what to think. I wanted to know if anyone experienced this?