I have frequent urinations and my urine is mostly cloudy and has a layer of oily film over it.it has been 7 months since the symptoms.my urine culture always come back negative for any bacterial growth.what else could it be?

Frequent urination but no pain (dysuria) by your statement. Negative urine culture confirmed you do not have bladder infection but you have frequency and abnormal urine appearance. Absolutely, cloudy urine with an oily film are abnormal. A formal urinalysis report will be helpful. Several systemic diseases can cause frequent urination but without significant change in urine appearance.