if the worm was on windows and now you are going to use it on mac it probably wont warm your mac.
What you can do is put the flash drive on windows again, on folder options make hidden files viewable, check if your flash drive has a autorun.inf file, if ti does delete it and quickly create a folder called "autorun.inf". Now remove and insert back the flash drive a couple times and check if the virus was able to replace the folder or not.
Most virus creators are dumb and didnt think on this. Kepe the autorun.inf folder in the flashdrive as precaution.