I met a girl last semester in a class and we've stayed in touch since then and gone out 3 times. Last time we saw each other was about 3 weeks ago. After the date she told me she was going to be out of town for a bit but wanted to see me when she got back. All the dates have gone well and I really like this girl and I thought she felt the same way. I texted her twice this past week and she still hasn't responded. What's the deal with this? Why would a girl lead me on like this to just totally shut me out? Should I wait around for a response, try calling her, or just give up?