ab/pelvic pain, blood in urine

  About 5 weeks ago I noticed abdominal and pelvic pain as well as some back pain.  I also noticed an increase in the frequency in urination.  My doctor found blood in my urine (microscopic) and  thought that I had a bladder infection.  Since then I have been on antibiotics four times.  My urine culture has shown no bacterial growth and only once had a trace amount of leukocytes.  
  I have only infrequent pain AFTER urination that comes in waves and then subsides.  I was wondering if I could have urinary tract or kidney stones?   I thought that I would be in much more pain.  What kinds of tests do stones show up on?  Thank you very much for any help anyone can provide.
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Dear Kristen,
Microscopic hematuria (blood detected in the urine under a microscope) and gross hematuria (blood seen in the urine under the naked eye) may be caused by a variety of problems such as urinary tract infections, kidney stones or any stone in the urinary tract, tumors anywhere in the urinary tract, etc.  They both deserve work-up which would include an upper and lower urinary tract work up.  The upper urinary tract can be worked up with an intravenous pyelogram (IVP) or ultrasound, both of which are radiographical tests.  Work-up of the lower urinary tract requires a cystoscopy, which involves looking into the bladder with a lighted telescope in the urologist