Turn it over and look at how it's printed. Does the print follow the threads like it should?
If it's printed crooked - I would wash and dry it - see how it wants to go - and then if it is crooked, trim it as well as I could and deal with it that way.
If it is printed crooked - you have two choices:
Work with it the way it is - everything will be off-grain
Trim it so that the edges are on-grain - you will probably lose part of the panel - some people reframe it with washings and make it look like it was intentional.