No, it shouldn't affect your cycle or the Pill's effectiveness. Those sugar pills are there as placeholders--just to keep you in the habit of taking the pill at the same time everyday. There's nothing hormone-wise actually IN them.
If you're taking the other pills at the same time every day, following all of the instructions given with the pill, you'll be protected.
That fourth row of "pseudo pills" are there basically to keep pill takers on a regular regimen of taking their pill. If you do not like to take pills or are forgetful, then this method is just to help keep you on track.
But if you know that you can skip 7 days and then start the following week, then you are ok in that respect.
Honestly, if you didn't know this, and didn't think to read the directions completely before taking the pill, the pill might not be right for you.Birth Control Pill and Alcohol