Best bet would be to discuss your situation with the motel owner/manager. Honestly, if you'll only be one week behind, it really shouldn't be a big deal.
If you haven't signed a lease with specific stipulations regarding late payments, length of lease agreement, etc., they might be able to evict you on the spot; same as if you were staying two weeks at a hotel on vacation and couldn't pay for the second week.
Talk with the owner/manager first, and quickly.

