I would remeasure the yardage after it's washed and dried. I believe that most patterns have a bit of a fudge factor built in, so if the shrinkage isn't drastic, you may be OK.
You may also make a sample block and see how much it really takes and figure the math from there.
If you run short, is it possible to make the final border a little narrower?
...or you could just buy more fabric. There's always room in the stash bin.