There is this female friend I like and to whom I asked to go do things just the 2 of us two times before ,and each time she had an excuse to not go without proposing another date instead. She wrote me a postcard during the vacations and I wrote her back and said she was happy I did. But we havent seen each other for a while and stopped initating hanging out with her and did not text her for a month. One night she writes me to ask if I would want to eat lunch with her the next day. I tell her yeah, and that day we meetup for lunch in a parc just the two of us, talk, laugh, for an hour and then when we had to leave I asked her if she would want to go see a concert with me for wich I have tickets. She says she would have loved to but that she has an exam the next morning so she can't. And that's it, haven't written her since.

I am not sure of what I should do, I feel like she doesn't really like me because its the 3rd opportunity she had to go on a date. Does she like me? What should I do? Try to forget her? Try more?