Am I a bad friend? Help please.?

Ok so last week my friend and I were talking about playing tennis today in the morning. Thursday I asked her if she had an extra racket to bring as I would be coming from my bf's house. She said she wasn't sure and had to see if her bro had one. I said ok let me know and didn't hear back from her for 2 days. I got her msg today that she sent on FB yesterday saying things look good for today...well its too late now. What should I do? :(