I was told that FLMA only applies to companies that are larger than 50 employees? Is this true? Are the rules regarding FMLA different from state to state?

I have worked for a company for about 14 months. The first 6 months I worked as a “sub” for them, but I still worked a full 40 hours a week and my checks still came directly from them. I now need to go on FMLA, but they are telling me that I am not covered because my I was not officially hired on from sub status until 8 months ago. Are they right, or does FMLA time include all of the time I worked for them, even as a sub?

Under the poster at my job it says you can take up to 12 weeks unpaid leave for pregnacy under fmla leave. Does this mean I can take as much of that as I want or is it up to the employer? Can they limit how much time I can take? I would like to take the full 12 weeks.