Hcg levels

My doctor said the levels are fine and within range. I told her it looks like my levels stopped doubling and asked her if it was normal and she told me to stay positive.

My hcg levels on 12/4 was 1649

My hcg levels as of yesterday 24100.

I’m six weeks pregnant and when I look at the calculator it says it stops doubling every two days around week 5/6. I am unsure if that is true.