Late with Letrozole

Argh. I missed my period and got a BFN. I’m on CD 31 with letrozole 5 mg (days 3-7) and my progesterone at CD 23 was 9.93. But the thing is... no period in sight! Had a tiny bit of blood on my cervix two days ago, but now absolutely nothing.

Am I out? Anyone miss a period with letrozole or get one late? Experience with this? First time trying letrozole.