Mr Salty's right, if no ammonia in a week, be careful, you've got zombie shrimp.
Be patient. It's hard because you want to plunge in, but many of us who have killed off their first batch of fish can attest that impatience is the worst thing for your fish.
Your water should start getting cloudy pretty soon, and you'll be able to smell them (that's going to be time to take them out). If you still don't read any ammonia, then you have a bad test kit or your testing procedure is in error.
Be patient!