Letrozole & Progesterone

My doctor prescribed me Letrozole to take on cycle days 3-7. He also prescribed Progesterone 200mg to vaginally insert twice a day. What cycle day did you guys start taking the vaginal progesterone? Also at what point did you stop taking it if you didn’t get pregnant that cycle? I sent him a message but the office hasn’t gotten back to me yet. This will also be my first and last cycle with this clinic because they haven’t really explained anything to me(besides the financial part of it) and it’s hard to get in touch with these people when I need to☹️