Give your tank some time, it can takes weeks to months for the second colony of bacteria to grow. Just keep pumping in ammonia and the BB should show up eventually.
And fisherjean, not all water testing is done with drops and water samples. I have seen some that are dip strips. I perfer the water sample testing, but I was confused reading what you posted so trying to clear it up.
Also, you could try letting the water run for a couple days and not change it so frequently. Give the bacteria a chance to settle in and get aquanted with eachother before changing the water again