I think it could be a possible prostate problem. You should seriously see a doctor and get checked out. It is not normal to urinate that often....
Some of the common causes of frequent urination are:
Excessive fluid intake
Urinary tract infection
Pregnancy -
h:
Prostatitis (infected or inflamed prostrate gland) - in males
Radiation therapy
Diabetes
I would be on the safe side and go get checked out. How old are you?