Progesterone Drop

Has anyone ever had their progesterone drop and the pregnancy still progressed well?

My doctor has been monitoring mine and has had me on progesterone suppositories since the beginning Bc my last pregnancy ended in a miscarriage.

3w6d progesterone level 24

5w6d progesterone level 14

Seems like a large drop to me? Doctor said some fluctuations are normal but they upped my progesterone suppositories to 400mg nightly. Has this happened to anyone else?