Since you say you forget the dreams until they come true, I'm a bit sceptical about how accurate your memory of the dreams are. It's possible you remembered something vaguely similar, and your subconcious filled in the gaps - sort of like change blindness or inattention blindness. It's also possible the deja-vu was just a feeling, and not actually indicative of any memory of a premonition at all. Definitely try the dream journal though, that should be interesting.