My lining was 6.5 on CD 12.. so ur just fine at CD 9. Good luck :)
I agree with bny...a 20mm follicle is great! The lining is right on the border of what they like to see, but you're only on day 9, so it should grow some more before you ovulate.
Best of luck!
I know the follie of 20 sounds great for day 9! and not sure about the endo metrial thickness though.. Are yall doing IUI, or a trigger shot?? are you on medications?? good luck! : )