Is it true that it is a federal law that you must take a pregnancy test prior to receiving anesthesia? state law? any states that don't require this?

No one wants to be: sued unnecessarily, and precautions must always be followed for any young woman of pregnancy age as a safe measure. Since most preop orders are simple blood tests, it's easy to do it with all of the rest. In the US if you are of childbearing age, you'll probably be required to do it, especially in a hospital setting, or surgical suite. In office procedure may be different.