I'm on tri-sprintec and skipped the last week of pills and started a new pack instead so I can skip my period for a important event, can I do it again next month for the same reason, and will I have successful results ?

I've never done two months, just one month at a time but I imagine it would work the same.
If this is something you need to do regularly (curious, why do you need to skip it?) you might want to consider talking to your doctor about seasonal (sp?), then you'll only have to have a period every few months instead of every few weeks