How important is is to take "the pill" at the same time everyday?

I take 28 tablet Yasmin, and I have read my information before, but I honestly did not pay attention to how important it is to take your pill at the SAME time each day. I do take my required pills daily, but not always at the same time. Somehow I have never wound up pregnant. So, I'm wondering if anyone knows just how important it is TO take your pill at the same time each day???