Twice in your urine test, blood was found while you did not actually notice. The sonograpy of your kidneys are normal as well.
Blood in urine is not a good sign. When it occurs occasionally, it is still fine. But not on a recurrent basis.
I would like to suggest you to wait for another week and repeat your urine test for blood. You may go ahead with the cystoscopy
. No harm in it.
I am sorry; I do not know your age to comment on your symptoms further.
Wish you good health.