I really need help with this situation ladies.?

I met this lady on the net (christian dating site) about 3 weeks ago. We chatted on the internet for about 3 hours two days straight, and then I got her number, been calling here since. Note that we are in our 20's. About 5 days later, I asked her if she would like to meet and do something together, she said that sounded good. Granted, she said I didn't make her uncomfortable at all, and it sounded like a pretty good thing is building up. She has a busy schedule, a little chaotic. So last Saturday, I left her a message and at the end of it I said to give me a shout any time, because she had that day off. It is now Thursday, and I haven't heard a thing, not one call or message. I just want to know from here, do I call, or do I wait?