Miscarriage and HCG

So, I should be 5 weeks and 4 days today through an

IVF

FET. Over the weekend, I was rushed to the hospital because of extreme back pain where I was bedridden. Then I started

Spotting... we saw the embryo and we were reassured the pregnancy was still valid. Then on Sunday I started passing clots. I got worried and was told to do another HCG test. My numbers increased but not by the amounts they were increasing previously (over 65%). My question is does anybody know how soon after a miscarriage does the HCG levels start to decrease? If I miscarried yesterday, will my numbers show it today? I have to repeat it again on the 21st, but I wanted to know for sure if I was still pregnant or not... any help? Or advice? I should probably mention my numbers

On the 17 6905 (5weeks 2 days)

On the 19 7900 (5 weeks 4 days)

Edit 1

Thank you so much for your prayers - they worked!! Baby is at 6 weeks with a good heart beat! Baby is a PGD tested bay, so i think we are in the clear!!!

Thank you again - and I wanted to say I am so sorry for all your losses, and I am praying for baby dust your way!