Clomid cd 3-7 vs cd5-9

How much earlier did you ovulate when you changed from taking clomid cd 5-9 to cd 3-7. I typically ovulate cd 20 when I take the clomid days 5-9. But the army is stealing my husband away the end of Feb. Which means I HAVE to ovulate by cd 16 or we are automatically out this month. What were your experiences? Do y'all think there is a shot of that happening or not so much? Please be honest 😊