How likely is it that Minoxidil will not work (or will make things worse) ?

[pick]

Hey all.

I am in my last year of college and have a head full of hair with no hair fall.
But I do have a quite a lot of miniaturization (hair thinning).

I know I will go completely bald in about 7-8 years. (genes)
But all I want to do is keep whatever I have for 7-8 years and then I don't mind *starting* to go bald.

I am thinking of trying Rogaine (Minoxidil).
1. Will the shedding be very bad?
I am worried of shedding a lot in my last year of college even if they'll grow back healthier later.
2. Is it possible that Minoxidil can cause a lot of shedding and then simply not cause a regrowth? (as in "unmasking" my baldness)

How probable are all these from your experience and hear-say?

Thank you