If you have a WiFi network and you try your site on maybe an iPad, iPhone and iMac then if they all use the same network you should see the same result - your ISP DNS will be the one at fault.
So if you use Google DNS on your iMac then it will load your site will the other two devices still use ISP DNS and the site probably won't load.
DNS updates normally come through in 24 hours, 48 hours or 96 hours depending on the ISP.
I use Sky and they update theirs each day at 3am so unless I use Google DNS I would not see these changes.
tl;dr yes the website will start working on all devices with just a clear/cache/flush over the next few days; else use Google DNS and flush in the meantime.