Should i start letrozole or wait ?

Sukanya

So the dr had told me to start letrozole for 5 days from 2 nd day of my periods. My lmp was on march 18th and on april 12 i had spotting only while wiping , nothing on april 13 and today also no spotting ..would it be implantation ? Or period coming ?

Should i consider april 12 as my first day of period ? 😕Am so confused . Also, i read we shouldnt take letrozole while pregnant . !!!

please help ....