How's it work, again?

Very new to this. But I'm puzzled now.. So we're trying to catch ovulation and the spike in temperature means a rise in progesterone. This rise in progesterone occurs after ovulation, right? That's what I've just read from someone else. So if this is true, we have to wait several days to be sure the temp. stays high to ensure that ovulation has occurred, yes? Doesn't this mean it would be too late at point, considering how short of a fertile window you have after ovulation? So if you experience a drop in temp., you ovulate, and the next day the temp. rises, but you can't be sure if you've truly ovulated for a few days, so you're still guessing because you can't wait those few days to TTC or it'll be too late. Please, can someone tell me what I'm missing here? I'm really sorry if this is a dumb question I'm just wondering if I've got my info wrong with how this works or if I'm over thinking the whole thing. Thanks!