got fired for being on materinity leave

There are several federal and state laws that may protect you depending on the facts in your case.  If there are more than 50 employees and you were full time for the last 12 months the FMLA would apply.  If there are at least 40 employees, the pregnancy discrimination act might apply.  You may also be able to argue gender discrimination if others are allowed to return to work after an illness or injury.  Speak to an attorney who can review your facts in more detail