Medical leave vs short term disability

Am
Need input... 
I have 6 weeks of paid short term disability that I was told "covers pregnancy". I also have 10 weeks of medical leave. My goal is to overlap the two as little as possible if not at all. I don't want to end up on bed rest my last month and having to use my medical leave, cutting my time short with baby. Ideally, if I have to be out before my due date, I would like to be on disability. And then wait until I have the baby to start medical leave. 
I want to figure out my rights before making a plan with work. I know they would want it all to overlap. Does anyone know? Or even know who the heck would know?