this happened to me previously.
if you're employed by a 3rd party agency as a W2 employee, your direct employer will inform you if your contract has been ended. and trust me, they will be quick to do so, since they won't be able to bill nike for your time and make their happy little markup on top of it.
if you're a 1099 contractor - that's a whole other situation but hopefully you have a signed contract or work order that communicates what happens and how you would be notified in a timely manner, in case of termination of the contract. if not, i suggest you get clarification in writing as soon as possible.