Feeling kinda sad tonight. Was invited to see a movie about a special needs child but they went without me

Last week a new person I was hoping to become friends with asked me if I'd like to see the movie unbreakable boy with her. I said I would. She did not say when the movie was playing I expected her to let me know. I just saw on Facebook that she went tonight with a group of ladies from the special needs parents group. I was not invited. I could have went. I'm feeling sad and excluded. I was hoping that maybe I could make a friend in this group and I guess Im not good enough