FET/Starting Estrace

So i was told to start estrace in prep for my FET on cycle day 1 however today is cycle day 36 and still no period which is odd for me. I went in for BW and Ultrasound today and just got a call from my clinic to start the Estrace even though i didnt get my period and to book a day 14 lining check.

Is it normal to start estrace with no period? Like what if my period decides to show up while taking the estrace?