Yes you can so basically use a back up method. if you can't remember to take your pills then get mirina or the shot so you don't have to think about lt.
Are you saying that you've taken every pill, every day like you're supposed to but instead of starting on Sunday you started on the other side (Saturday) so you're not taking the pills on the day that the card says? Personally I've been taking my pills like this for years. I started the first pill which said "Sunday" the day after my last non-pill period which was sometime in the middle of the week. When I switched doctors, I got switched pill types (US vs Australian) they swerve around from left to right depending on the day, I just take them as if they don't. (Every week I go left to right.) I figure one red pill is the same as the others so it doesn't matter what day it's taken, as long as it's taken and taken the same way so I don't get confused. I have never missed a pill or taken it more then 2 hours later than my set time. I've also been on the pill for about 2.5 years and haven't gotten pregnant.
Now stopping suddenly from taking the pill can and probably will mess up your period. Don't be shocked if you start spotting early, have a "odd" flow (too heavy, light, or long), feel painful cramps, bloating, nausea, or headaches. Also because sperm can live up to a week inside a body stopping them yesterday means that you're not protected all next week while you have potential swimmers inside! Meaning you could likely get pregnant because you stopped taking the pill right after you had sex. If it isn't too late I think you should follow your next week of pills. Otherwise well it's not too late to take the morning after pill...
Ya highly likely actually.... If you don't want to be pregnant you need to take birthcontrol