Well, you have discovered some of the issues with "sensitive" tests. All your urinary test result says is that there were some "atypical" cells present. Yes, bladder cancer can cause this....but these tests are notorious for "false positive" results, indicating a problem when none is present.. For example, if something like a low-level infection or some other irritation of the bladder lining is present you might well have "atypical" cells in your urine. This result is just an indication that further examination is in order. It is NOT diagnostic by itself.
Many things can cause microscopic or visible urinary blood, and most are NOT bladder cancer. In many cases, the cause is never found as you discovered five years ago.. This is why so many physicians do not even do a test for urinary blood routinely (and this is subject to differences of opinion.)
Your urologist now does need to do a TURB to see if there is any sign of cancer. It may very well be that there isn't any. In that case he will probably want to re-check you fairly frequently for a year or so.
Wishing you the best
Sara Anne