No, it really can be any day. Though a 14 day luteal phase is very average, so that means on average in a 28 day cycle, with a 14 day luteal phase, you would ovulate roughly day 14. But it doesn't have to be the case. You could still ovulate earlier or later and have a longer or shorter luteal phase. With my last two pregnancies (one ended in mc), I had a 28 day cycle, I ovulated roughly CD13-14 in one (I think it was actually at night on day 13, so kind of in the middle of those two days) and CD14 in the other. But it doesn't have to be like that. It really just depends on your cycle and what's normal for you.