How exactly does Yaz work?

I just stared a new job this month so I have been really out of it, and so I havn't been taking my Yaz EXACTLY on time everyday like I have been... and one day i missed so I took two the next day... does it still work even if I don't take it on time everyday? I am usually very careful and take it at the same time, but like I said, I have been really tired and forgetful... helpful answers only, please