I want to avoid my period 9/27-10-17 for my wedding/honeymoon. will start birth control. when do i start bc to avoid bleeding during time mentioned?

Start now, good luck: If you have not yet started the pill, start it with the first day of your period. You will want to be starting a new pack 9/25. Counting back, that means you will also be starting new packs 7/3, 7/31 and 8/28. Whenever you start this month, take only ACTIVE pills, no inactive pills, until 7/3 (or until 7/31 if you can't start until after 7/3). Ignore irregular bleeding. You should be OK by 9/25.