TN Finished - Final Pay

I am working at an academic position and my TN expires May 20th. However my final paycheck will be received on May 28th. The HR person here says this is alright (since I'm only being paid for work done prior to May 20th), but I'm not sure how many TNs she deals with. Is she right, or should I fight to get the final check before May 20th?

This is fine. Most places are usually a week or two behind on pay.

Thanks!