These things happen from time to time. What I have done in situations like this is sell what I can, meet and great folks and pass out business cards. The more places you get seen the more likely it will be that you will have return customers and good referrals from them as well. It took me about 3 years to get a loyal following of folks that would wait for me at several of the later shows so do not get discouraged. Remember to have fun and talk to folks you never know if that is the one that will buy or not. Try to stick to juried shows as they tend to be better managed.
DW