Beta levels

I had a blood test to check beta levels at 12Dpo and it was 105. The nurse said it was pretty low and are concerned. I had my blood taken again yesterday which would be 3 days later due to the weekend. I will be getting my results tomorrow. What is a normal beta count for 12 dpo?

Update: beta levels are 722. Going in again for another draw to check if it doubled. My primary dr is still concerned. Won’t be able to see the ob until July 8th.

Update: HCG is 1,890 48 hours after 2nd draw. Dr is still concerned. I thought as long as it doubles it’s ok. What’s a normal range for 18 dpo?