I always reccomend disclosing it. Most people don't really consider the fact that people with speech impediments exist. This catches people off guard, and they don't know how to react or think about it, or they may be worried that there's something "wrong" with you. If you disclose that you have a stutter, they will know that there's nothing wrong, it's just how you talk. They will know what it is, and they wont be caught off guard. Of course, do what you want to do, but disclosing it will only ever help you, really!