Hcg level question

I went for blood work Monday (7/19) and it came back at 40. Went again today (7/21) and it was up to 77. It was 46 hours between blood draws. Should I be worried that it didn’t double? I had an ectopic in 2019 and 2 chemical pregnancies this year (those never even hit 20 though) but I can’t even get excited yet. I’m so nervous 😞 based on my last period I’ll be 4 weeks on Friday.