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.