FMLA vs Short term Disability

I thought I posted can't remember. I have been advised that I am no longer able to utilize FMLA due to having a schedule change in order to accomindate my childrens therapy(still worked 40 hours a week). But now my HR manager has advised me that I can not use FMLA. She has assured me that my position will be the same and that I can apply for short term disability. PLEASE SOME ONE HELP ME....... I am so confused. Marah