Hcg 10 at 5dp5dt (frozen)

I just left the ER while out of town— turns out I have a cystic mass in my neck that needs to be biopsied. When they did my blood work they did Hcg as well. At 5dp5dt I thought 10 was promising! I was thrilled because it’s so early to have anything! ER dr came back and said I’m not pregnant. I told him I thought it was a good sign because it was still so early but he was adamant that at this point the Hcg should be higher and that I’m not pregnant. (He was so mean) Naturally I burst into tears when he left.

I called my nurse at home and she said this er doc is an idiot.

Has anyone else ever had a blood test super early? Or math stars that can estimate where they would have been 5dpt with a positive beta?