If there is a little blood found in my urine test, could it be either due to taking aspirin before the test or due to strenuous exercise ?

Blood in Urine: Either the aspirin you took or your strenuous exercise could have been responsible for the blood found in your urine, but so could have many other factors . The important thing to remember is that blood in the urine is not normal and is a warning sign that something may be wrong and be in need of further investigation and / or treatment. I highly recommend that you see your doctor.

Hematuria: Blood in the urine is abnormal whether it's microscopic or grossly visible and aspirin or strenuous exercise should not cause it. If only a couple of red blood cells are seen in a microscopic field, it may not indicate serious disease. However if it persists, a cytologic exam of the urine, urine culture, prostate exam and imaging of the kidneys and urinary bladder are indicated.