Canceled 7.1 Preview Now it's Stuck on Loading Screen

PLEASE SOMEONE HELP!! I need help! I was using the 7.1 preview. I was on the store page on one of our products and decided to adjust a button style. I was able to do that but could get to the other pages so I canceled the preview to start over. Now it's stuck on the loading page and says not to refresh or close the window. What do I do now???

I think the web browser just got stuck and I hit refresh seems to be okay now. I'm just nervous about doing this.