Je n'ai pas encore trouvé le trésor !
I haven't found the treasure yet!
Je ne pense pas encore à mon avenir.
I don't think of my future yet.
It seems to me that "not yet" expresses something that's ongoing, so should always be in the present like the second example. In the first example I'm still searching for the treasure, so shouldn't it be in the present? Is it the "haven't" that changes the tense?
Thanks in advance.
