Need advice on really long fishless cycle. The problem - lack of nitrates

Thor:

>In your first post, you mentioned "lack of nitrate" and "0ppm NO3". So I thought you have never had any nitrate in 7 weeks of fishless cycling.
>In your second post, you mentioned 4 weeks ago you have had nitrate concentration of 20~40ppm. 
>So, which one is it? 

My fishless cycling is split in two parts - the first = high/stuck NO2 and the second one = no nitrates. 
During the first part I had NO3 reading of 20-40 ppm but at the same time NO2 stuck to more than 5 ppm. 
During the second part NO3 reading is 0. 
Hope this should clarify things