Help!!! What can it be ?

I’m 33 weeks and I have to pee frequently and sometimes if I’m not quick enough some will come out , I’m having mucusy discharge and when I hold my pee till I find a bathroom I cramp up with pain .. what can that be like is it something or just normal . This is my second baby but I never had this with my first . My pee doesn’t stink or have a cloudy tint , neither does it burn or hurt ... just curious if I should call my doctor but don’t wanna be that patient that cries wolf for anything that’s not even anything ....