I'm 20 year old male , i smoked about 6 months (5-6 cig a day) , i quit about a month, three days ago i had blood in urine , after it disappeared, my doctor said it just infection ,i have not found blood till 3 days but I need to urinate every 20-25 minutes. I have not any burning and pain while urination, i just feel uncomfortable after urination like my bladder is not completely empty,and i need to urinate again I didn't took care of my genitals very good , I didn't use to shower for days while exam  , and i have some bad habit about not cleaning it after masturbation. I'm worried that if i have some major disease like cancer because my grandfather had it. Sonography is completely normal.