Fair enough.'Playable' is not the word I would use. Claire can become pregnant at the end of High School and/or College and have an arc where she makes decisions about that event.
In the main game (Act I and onwards), there is the chance she can become pregnant. That would be the only place where it becomes 'playable' but given the abbreviated timeline planned in the game, it's highly unlikely she would bring the child to term -- and if so, would result in a Game Over anyway.
So the fertility tracker only matter for HS and college? Or do you plan to use that as obstacle for her mission?
Like she only has money to buy either the treatment or some other thing, forcing her to choose, etc etc.
Just asking