Did this girl get my texts or not?

So there's this girl that I wanted to get to know. She moved to Florida a little while ago, and about a month after she left I texted her. I didn't get a response, which I thought was kind of unusual seeing as she usually replied to my text messages while she was here. Then I realized that she may have changed her cell phone area code because she was going to college in Florida and would probably need a new code. How can I verify that I mixed up the codes and that she's not just ignoring me? Or how can I know if she received the texts or not? I don't think she would brush me off, but I don't want to be a pest and keep texting her if she's not gonna reply.