Yes, you should see your doctor to determine the exact origin of the symptoms. Most likely the symptoms are a result of BPH; however, you certainly want to rule out the possibility of prostate cancer. 

Doctors use the digital rectal exam (DRE), which is typically done during a regular physical exam for middle aged men.  The goal of a digital rectal exam is to detect cancer in its early stages, when treatment is most successful.  Because the prostate gland is an internal organ, your doctor cannot look at it directly, but since it is situated in front of the rectum, he can feel it by inserting a gloved, lubricated finger into your rectum.

The physician will probably also conduct a PSA (Prostate-Specific Antigen) blood test, which is also a screening test for prostate cancer. 

Acute Urinary Retention is a serious complication of BPH in which one cannot urinate at all resulting in a distended bladder associated with pain.  If you cannot urinate and have pain, consult your doctor immediately or get medical attention at a hospital emergency department.  If left unattended, the urine in the bladder could back up into the kdneys resulting in serious medical problems.  The immediate treatment is to remove the urine from the bladder by inserting a catheter through the penis into the bladder.