The CT Urogram is a good test, but it can't see everything that a cystoscopy sees. It cant' show flat tumors like CIS, and small tumors may not be visible. The cystoscopy is just as important to definitively rule out cancer as it is to find it early and treat it before ti becomes a problem. Even though tests make patients nervous, one must always rule out the worst case scenario - in this case bladder cancer. You could never be truly at peace without knowing for sure that you don't have cancer, and if you do, it's best to find it now rather than later.
All of us have been scared before our diagnosis, and we have the pleasure of being scared again at follow ups because we worry about recurrences - but there is life after cancer. I'm 7 years out with a high grade cancer and have never had a recurrence.
You may have nothing, so try to stay clam. If you have something, you'll be treated, and we'll all be here to help you deal with it.