Does she have interest in me?

a girl i like is new to the school and i have been talking to her in class because i sit by her and i finally asked her to go lunch with me and she said yes and was pretty happy about it. I thought it went really well and she was laughing and i learned a lot about her. so i asked the next day if she wanted to go again but then she said if she inst doing something else then she will go with me. and she ended up not going with me and she ignores some of my texts. Does she not like me ? . or should i wait longer to see more signs. i have school tomorrow with her again and i don't wanna be dumb if she obviously doesn't like me. and i know its kinda early to tell but i just wanted to know ;/