IVF pregnancy

Heather • got our miracle on the way after 3 Yrs trying 2 ectopic 1 chemical and 1 m/c

need help I am 9w 2d pregnant I'm on progesterone shots and prometrium tabs twice daily vaginally. last week at 8w 2d my progesterone level was 24.1 this week it has gone down to 17 does that mean something bad? please help had a 8 week ultrasound in July and I cannot go thru that again