Switching cycle days.

Right now, my doctor wants me to take clomid cycle days 5-9 but I'm deciding whether or not to switch it on my own to either cycle days 2-6 or 3-7.. Will this be a bad choice to make? And what would I tell my doctor if I switched the days on my own? She will want blood drawn on CD21. Insight would be lovely please. I'm at my last straw. Last round of clomid and I'm very discouraged...