getting current user cart

[ydl]

I am trying to get the current user cart in the:
calculationh.php and / or padded.php

The goal is to check the current price in the cart + last half year purchases and comper it to a value which is stored in the shopper / user data

I used the function:
    $cart = VirtueMartCart::getCart(false);

BUT the $cart->products is empty (while in the cart module it is not empty!)

any idea how to get the 'cart's products' list?