Does hcg stop doubling every 48 hours?

Meagan
I had a mc in sept so my dr is monitoring my hcg closely. On 2-2 it was 26. 2-4 it was 92. On 2-10 it was 2452. I did my final today and it didn't double. It was 4087. I'm just curious if it didn't double bc I'm over a certain point. Is it going to take longer for it to double now? Like 3-4 days? I'm scared