You usually get your period within a couple days into the "sugar" reminder pills. I know I would start the sugar pills on a monday, but sometimes not get my period until tuesday or wednesday. That was just how my cycle was.
If you do not want to have a period for a certain special occasion it is indeed ok not to. Instead of taking the sugar reminder pills you just start your next new pack of pills right away. This should prevent you from having a period.
As a matter of fact, there is now a pill where you only have a period like every four months, or so? I saw it advertised on tv, but can't remember the name at the moment. According to the new studies it is ok, and even healthy, for women only to have a couple of periods a year.