I bought my first rogaine set today.  I wasn't sure when it would permittable to use it since it's only been a week and a half since the surgery.  Based on my readings, when the scabs fall off or two weeks, whenever is more comfortable for us.
From:
http://www.baldtruthtalk.com/showthread.php?t=2956

Same posting mentioned hair shcok and dormant phases of follicular growth.
Hope this doesn't happen to me.
I ordered the propecia.
Between the two, in about a year, I should amazing thick hair.
Less pain today, although still tingly.