How To Treat Bladder Cramps?

My period was late last mnth & it hasent came on so far I took a pregnancy test 2wks ago & it was negative I went to the Dr. Got a pap & horomonial level check everything came back normal. Yesterday it felt like my bladder was about 2 bust! It was a lot of pressure when I pee"d afterward I cramp 4 b0u a hour.