Yes. The False Claims Act prevents your employer from discharging, demoting, suspending, threatening, harassing, or discriminating against you for taking lawful steps towards investigating a violation of the False Claims Act.
However, be advised that your employer may take action against you anyway, and it could be years before you receive redress for these wrongs in court. If you have been fired for whistleblowing, you will likely need to hire an experienced attorney who can fight your termination under applicable state and federal laws.