How to check if user is following the other one before following or unfollowing (attach)

I used many to many relationship in my user table to make the logged in user to follow another one, but I didn't figuerd it out by myself, I checked what others did and tried to do something similar and it worked. In my methods I have:

function follow(User $user) {
    $this->followers()->attach($user->id);
}

function unfollow(User $user) {
    $this->followers()->detach($user->id);
}

which allows me follow.

the tables are related with a function something like:

return $this->belongsToMany('App\User', 'followers', 'user_id', 'follower_id');

now I pass the $user value by the controller and the controller is pretty simple:

    $userId = User::find($user);
    $willfollow = Auth::user();

    $willfollow->unfollow($userId);

I know the controller information is probably not needed but incase it is easy to check the relation withing the controller I would prefer to do it that way, cuz I'm obviously don't have that much knowledge of metod use.

Laravel 5.4

Thanks for any help.