Never assume the ability to walk means your ankle isn't broken or badly sprained. Putting weight on the injured joint can worsen the problem and lead to chronic instability, joint pain and arthritis later in life.
It's best to have an injured ankle evaluated as soon as possible for proper diagnosis and treatment. If you can't see a foot and ankle surgeon or visit the emergency room right away, follow the RICE principle -- Rest, Ice, Compression and Elevation -- until medical care is available.