Should I Start Gestranol Today Because I Ovulated Early, Or Wait Until Day 16 As Prescribed?

Hi, I ve prescribed letrozole 2.5mg for conceiving with PCOD. I ve completed the 6 day course and today is my 10th day of period. I ve noticed egg white cervical mucus today, but there is no other symptoms of ovulation. My doctor also suggested gestrenol for the 16th day to 26th day. If I ovulated today, should I take it from today or as per the advice of my doctor?