Cycle days to take clomid

Nikki • Mama to twin boys Milo James and Luca Matthew 💙💙

Just wondering why some people are told to take clomid cycle days 3-7 and some on days 5-9 or any other days. Is there a difference with how they work? I’m taking my first round of clomid for weak ovulation/low progesterone and my doc has me doing days 5-9. Just curious if there’s any specific reasons behind it. 🙂