Has anyone experienced this ?

I’m supposed to be about 5 weeks 5 days ( if I ovulated when I think I did)

And my last beta was on Wednesday and the result was 503 and then 560 in the morning when if doubling should’ve been between 650-700 the next day.

I was in emerg for pain and pink spotting but they couldn’t see anything on the ultrasound.

The last 4 days I took three tests and they have gotten lighter.

I know people are going to say stop testing but I had a very traumatic miscarried already and so naturally I am anxious and very concerned when my HCG isn’t the best and I’m experiencing pain and spotting.

Has anyone experienced this ? Is this normal? Should I worry? If you’re having a chemical how long does it take to miscarry if your levels drop?