You're human - not a robot. You're allowed to care, man
I don't think she's playing anything with you. I believe she's being genuine with her excuse. Before jumping to conclusions, you shouldget to know her more. I tend to not pay attention to anything in the beginning because it can and will throw me off my game. Once you get to know the person, you'll be able to make accurate judgments about whether or not they're being genuine.
If you choose to drop it, I recommend giving it one more shot regardless of how you think it'll turn out. If you drop it, you won't know what could have happened nor would you have learned anything. Keep trying, but as a learning experience.