Birth control failure

I’m not totally sure how it works all around but I know that birth control pill stops ovulation. Let’s say your taking the pill perfectly (same time every day), but for some reason the hormones in your pill is not enough to keep your body from ovulating. First off, is that possible? Second off, if it is possible, would you be ovulating around the time that you normally would if you weren’t on birth control or could it be at any given moment?