Low HCG levels? Conflicting/ confusing information

Hi there. I had a blood test on Saturday when I would have been around 4weeks 5 days (at the latest) and my levels were 570.

I’m worried that this is too low. According to the results interpretation chart my dr gave me, it definitely is. But other charts I’ve seen online put it in a normal range. I’m so confused and worried.

Dr just said “don’t worry about it” and moved on... I’m kicking myself for not asking more questions now. Any insights would be so appreciated!