You would actually be 4 weeks, not two. Test show how old baby is. But Drs calculate your due date from the first say of your lmp. So your 4 weeks: -)
As far as cravings go eat girl eat! Lol
But remember you only need 300 extra calories a day to maintain a healthy weight gain. (Example a peanut butter sandwich and two hard boil eggs) so you are not actually eating for two. Baby gets all the good stuff from what you are eating. If you don't eat baby just takes from your body. that is why prenatal vitamins are important.
But.... congratulations!!! I hope you have a healthy pregnancy, labor & birth. :-)