Lupron depot

I am curious as I am preparing for my 2 month Lupron Depot Suppression. My doctor told me to take birth control pills for 10 days prior to the 1st dose (in December) then repeat the same 10 days of pills in January and then do the 2nd dose. But, most people I hear have used Letrozole along with Lupron Depot and have had success getting pregnant during transfer. I am doing a medicated FET transfer in February and I am just nervous as my doctor said they usually don't use Letrozole with suppression. I am just nervous that I am not doing everything correctly to ensure that I will be successful. I have not been formally diagnosed with endometriosis, but my receptiva test came back positive for overexpression as in I may have endo. But I don't have the usual endo symptoms. Anyways, this will be my first transfer in February. For those of you that suppressed before a transfer, is it ok to use just birth control pills and Lupron depot without using Letrozole?