What Could Cause Frequent Urination Every Few Minutes During The Day And At Night

I had for 5 days now pressure and ruining every 5 mins or less all test results on urine negative all labs are normal was put on antibiotic and a med to help with what dr says pressure is spasms and for now he says we will treat as you a bladder infection until culture are back / 3 days cultures. Back today and are negative so what could this be as having a vag ultrasound tomorrow however can’t stop the constant urinating every 4-5 mins all day and less About 20-30 between intervals @ night. Any ideas as to what this could be??.