Asthmatic and Pregnant

Has anyone had any issues with their preventer/reliever? i.e been advised to switch to different brand or lower dose? I'm on my second pregnancy and used my inhalers as normal with the first but I don't remember haiving the same breathlessness issues I am having this time around (I am carrying extra weight this time which doesn't help). Going to the dr tomorrow as been having trouble getting a script done over the phone as the nurse is hesitant do one with me being pregnant