Hcg doubling time

So last week my HCG doubling time was 1,5 days. It went from 508 to 2104 in about 60 hours—I had it done on a Wednesday and a Saturday so 3 days apart, not 2. Now I had another one done yesterday and it’s 5445–double time is now 2.2 days from Saturday to Tuesday. Is it slowing down? Should I be worried it’s not 1.5 day doubling anymore? If I’m calculating right from Saturday to Tuesday it should be 64something if my doubling time was 1.5 days. I’m 5.4 weeks today

I’m constantly worried as I had a MMC in march