After 15 days of antibiotics i still feel pressure from my uti...should i go back to the er?

Needs Evaluation: It would be unusual to still have symptoms of a UTI after 15 days of antibiotics. It is possible that the bacteria causing the infection is resistant to your antibiotic. It is also possible that you have some other problem such as interstitial cystitis. You shouldn't need to go to an er. This could be evaluated by your primary doctor or at an urgent care.

Hopefully to your Dr: Symptoms suggest that you may still have a uti. Antibiotic given in an er may not be effective against the bacteria causing your uti, or else the bacteria may have acquired resistance. This occurs most often with the penicillins. But ers are designed for emergencies and you and your insurance (even if you are covered by medicaid). You are always better off with a primary care or family care dr.