Other than drinking excessive fluid, UTI & diabetes, what else causes frequent urination?

Frequency. Over active bladder, interstitial cystitis are also common.
Many causes. Overactive bladder, interstitial cystitis, anxiety, multiple sclerosis, small or small functional bladder capacity, urethral or bladder neck polyp, vesic-ureteral reflux, caffeine, certain food dyes or spicy foods +/or acid producing urine foods and beverages and certain allergies.

Related Questions

Other than pregnancy, UTI & diabetes, what else causes frequent urination?

Irritation. The bladder can be irritated by a foreign body like a uric acid or calcium-based stone. It can be affeced by interstitial cystitis where there is a defect in the bldder wall with resulting irritation and low volume. A cancer can cause the probem as can certain types of incontinence and incomplete voiding. Have your gynecologist or urologist check you out.
A lot. Sexually transmitted diseases, stress, small bladder, alcohol consumption, overactive thyroid gland, water pills, elevated calcium level in blood, stroke or nerve trouble that control the urinary system.

Cause of frequent urination? Negative for uti, diabetes, negative blood test, and negative ultrasound?

Frequent urination. Assuming you have no symptoms of burning on urination or pain, causes to consider include small bladder syndrome (some people's bladders are just smaller than others) or interstitial cystitis (but usually associated with significant discomfort). Certain vaginal infections (notably herpes, but also yeast or gardneralla) can cause frequency, but also usually associated with discomfort.
Need more info. This, without other symptoms and/or signs, is a nonspecific finding. It could be stress, or anxiety. It could simply be from drinking too much fluids, or coffee and/or soda. It could be nothing. It would be a good idea to wait a few days and try to relax, and if it persists, see your doctor for further work-up along the lines of possible urinary incontinence.

No UTI and no diabetes. Frequent urination with small amounts what could it be?

'overactive bladder' Frequent urination could be 'overactive bladder' or 'overflow incontinence'. An ultrasound can differentiate the two.
Answer #3, ? OAB. You may have an overactive or small bladder which will respond to medication. Please see a urologist or uro-gynecologist.

Frequent urination and very thirsty? No diabetes and not a uti?

More info. You need to undergo a detailed history and physical exam followed by possible lab work and imaging studies relevant to the findings. For this would suggest seeing a good general internist or family physician who will spend the time and interest necessary to work this out.
Frequency? OAB. Interstitial cystitis diet, caffeine anxiety or stress or any combination. Thirst could be due salty or high salt containing foods like soup mix or canned soup, mouth breathing, lack of humidity, xs sweating & also stress or anxiety.

Frequent urination and negative for diabetes and a uti?

Other causes. Prostate enlargement/cancer, neurogenic bladder (nerve problem, stroke), drug side effects (diuretics, theophylline, psychotropic, antihistamines), diet choices, interstitial cystitis, overactive bladder, pregnancy, bladder cancer, urinary incontinence. No way to tell without asking more personal questions or examine you. Please see your doc if this continues.
Overactive bladder. Can be due to all the cause listed in my previous reply to your question rearding urinary frequency plus interstitial cystitis, i.e. Intake volume, caffeine, acid urine producing foods and beverages, stress and anxiety.

What are tests that could determine what is causing my frequent urination. I had a test and got a negative result for diabetes and a uti.?

Many. There are numerous tests. It can be range from blood to urine to ultrasound to mri. Instead of viewing only tests, it would be good to have a complete history and physical. There are many causes besides diabetes and a uti. There are other causes such as siadh, sepsis, pregnancy, and others.