I'm afraid Tazman, although correct, is generalizing - many municipal water supplies (and my well water) CAN HAVE zero ammonia and nitrites, but have 10-20ppm+ nitrates !
It takes 4-8 weeks to cycle a startup tank assuming there is a source of ammonia. It's often at least 4, sometimes 6 weeks even with a bio-seed of some sort. Unless you follow and measure a spike in ammonia and see it drop to zero, then see an increase in nitrites and subsequently see it drop to zero as nitrates then increase, you can not judge a cycle based on nitrates alone.
There is one exception. Make sure and test your source water carefully to determine your base line. THEN if/when you see significantly higher nitrates in your tank, you can presume that nitrosomona and nitrobacter bacteria are doing their job.
(Based on your previous posts and the timeline, I'm not sure your tank is cycled yet)
Note: Also be careful using any liquid test for nitrates. There is an element (API Test for example) in regent #2 that will separate out of solution. If you do not mix very, very well, you may get a deceptively false low reading.