Why take Femara for 7 days?

Briana
I have been taking Femara for 3-4 cycles on either days 3-7 or 5-9.  My doc said to do 7 days, days 3-9.  What benefit is this to me?! Just curious as to what the extra days will do for me. Hoping to do <a href="https://glowing.com/glow-fertility-program">IUI</a> this upcoming weekend :)