Drop in progesterone while pregnant from FET…HELP!!

Question:

Had my 6w5d check up today and my progesterone took a nose dive . I did a natural fet so my body is producing its own hormones. HCG is great over 26000 estrogen is good my progesterone was 14 and dropped to 9.3 randomly, I am on suppositories and they are having me start PIO to get it back up.

My ultrasound was ok, it measured in range but I measured 6w2d instead of 6w5d we saw the heart beating away.

Is this indicative of a future miscarriage? Had anyone experienced a progesterone drop and been ok?

Sorry for two posts today!!