Tri Femynor

I have never been on birth control in any way before, and I've just been prescribed Tri Femynor, you know, the pill. I understand everything about taking it, the only thing I'm concerned about is the number of pills vs my cycle. I typically have between a 32-36 day cycle, but the pill pack contains 28 pills (21 active, 7 placebo), so do I need to worry about starting a new pack mid cycle or will my cycle change to fit the hormone schedule of the pill pack?