What does the whistleblower law do? Does it protect you if you report a company for government fraud?

You should definitely be represented by a lawyer with expertise in filing and litigating cases under the False Claims Act. You cannot recover any money for merely reporting Medicare fraud. You can only recover money (generally 15-30 percent of the Government' recovery) if you have filed a case under the False Claims Act. Moreover, you have to be the first person to file such a case to be eligible for a share of the Government's recovery. If you wait and someone else files a case before you do based on the same or similar allegations your case will be barred and you will recover nothing.

The False Claims Act does have an anti-retaliation section in 31 USC 3730(h). This section was just amended a few weeks ago. You need to talk to a qualified lawyer about the facts in your case to try to protect yourself in the event you are fired later on.

Many False Claims Act cases are done on a contingent fee basis, which means that the client does not pay by the hour. So that should not be an issue.