Why Don't i have 3G on my iphone 4s from sprint? There's just a cirlce spinning

It all started since yesterday at 6 pm

Try this instead http://forums.zzkko.com/topic/2520-help-me-win-an-ainol-novo-8-find-please-just-view-this-and-reply/page-4#entry14081

Check your data APN settings.

Settings > General > Cellular > Cellular Data Network

If that's fine & its still an issue, check with Sprint about it.