Anyone get pregnant taking clomid or Letrazole days 4-8???

I'm kinda confused. Today I'm CD2. I thought I would be taking letrozole days 5-9 but today when I went to my appointment at my fertility specialist the nurse prescribed me letrozole and told me to take them this Saturday CD4 to next Wednesday CD8 and then made me an appointment on CD13 to have an SHG with saline bubbles instead of an HSG that uses dye. And she prescribed me a trigger shot also but told me to keep it in my refrigerator and not do anything with it until they say. I thought people normally take letrozole or clomid on days 3-7 or 5-9? Has anyone got pregnant with 4-8?