Bloody urination once aday ...... before the bloody urine comes out pain in lower abdomen and sides and in the penis?

You must see an MD: This is serious , i don't have a good history.Did it follow any action , injury ? At your age you must see a urologist. You may have a stone.

See a physician: Though not necessarily serious, visible blood in the urine (hematuria) is never normal and should be evaluated to determine the cause. In a 20 y/o male, hematuria associated with pain, possibilities include uti, prostatitis, and stone. Would recommend you see a physician in a timely fashion to obtain appropriate testing and treatment.

Bladder/UTI: You already have a serious infection/inflammation of wither your bladder, urethra ( penis) or both. If having unprotected sexual intercourse get STD screening and no matter what, get examined,tested and treated with antibiotics. No sexual intercourse for 10 days. Urinary Tract Infection Instructions: Drink 8-10 8 oz. glasses of fluid: water, Gatorade, PowerAde, Vitamin Water, broth, bullion, consume, clear soups. Abstain sexually for 1 week. Cotton undergarments, no tight clothing below the waist. Recheck in 1 week if not improved