Hello and welcome to HCM. Thank you for your query. Let me help you with some information which will help you both understand and further monitor yourself till you achieve complete relief from your infection. First of all, all your symptoms need to be related to a laboratory investigation which will then confirm a urinary tract infection (UTI) and only then can medication be advised. Now coming to those investigations and their uses. At first, a urine analysis which will provide vital information on the possibility of a UTI. In your specific case you will also have to request for a urine culture examination. This is a very important investigation. This investigation not only confirms the infection, but also confirms the infection-causing organism and provides information on the most suitable antibiotic that can be used to treat your condition. Why is this information relevant? Because, each individual has a specific response to a specific antibiotic. An antibiotic which is effective in one individual is called a susceptible antibiotic, but the same antibiotic can prove to be ineffective in another, this would be a resistant antibiotic in this individuals case. Thus, there exists a possibility that you are resistant to the antibiotic you are using. Thus this antibiotic will not be effective and will not provide any relief to you. If it were effective, you would have noticed a change from the second day itself, and by now you would be completely relieved of your symptoms and condition. Please visit your doctor and request for a urine culture examination (takes 24-48 hours to report a result), in the meantime ask your doctor to change your antibiotic as well. You should consume plenty of water, also add cranberry juice to your regimen as it has shown to have added benefits in relieving UTI-related symptoms. Another aspect of your presentation might have to be further investigated. Although flank pain (lower back) is commonly seen in patients with a UTI, this is at times also due to other causes. I would advise an abdominal and pelvic ultrasound as well, just to rule out all other causes. I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you. Best wishes.