Dating Question

I have been talking to this girl the for about a week now at the gym. She makes the protein shakes. The most recent time I saw her we talked for about an hour-hour and a half because I was told by my boss to go into work later and I go to work after the gym. It saves me gas instead of going home. Anyway, she was contributing to the conversation. I asked her if she wanted to catch a drink sometime. She gave me a nonchalant "sure" and gave me her number. However, I want to throw out there that I am just getting back into the game after a 4 year long relationship so I was a very skittish/shy when I asked. I waited the standard 24 hours and texted her. She never texted back. What would you guys do in this situation? I am going to see her at the gym next time I go. I was thinking about when I get my after workout shake break the ice by being straight with her and saying something like "Im sorry if I spooked you when I asked for your number. I stepped out of my comfort zone asking a pretty girl for her number" but be nonchalant about it and play it smooth. Judge her response. If she is stand-offish then obviously leave it be and dont bother again. But what do others think of this and how would you approach the situation? I am not trying to come off desperate because I am not. My personal image is everything and I over think things and work myself up thinking I will look like a creep lol