Make sure your kale is fresh (I find the pre-packaged "chopped" kale goes bad quickly). Also, use only a little to begin with because it is strong. You can also mix kale and spinach if you like the taste of spinach better, but using all spinach is fine too. Just giving you some options if you want to try to use up the kale or if you want to try to get some in your diet.
40 weeks and 3 days - Going back to my original thought that the baby belongs to your fiancee, "yes", it would be highly unlikely that you would be over 3 weeks late - the doctors would have accurate dates by now and would not have let you go that long.
Here's a great page with some resources for you to read on how to help your body go into labour naturally, and how to know when labour is going to start.
Wishing you all the best! Please post back with any questions.