Amniotic fluid leak? Has this happened to you? Why does it happen and was everything okay?

I think I'm leaking amniotic fluid. I am almost 29 weeks. I noticed something was going on down there so I laid down for 30 minutes and then stood up to see if there was a "gush" and there was and now I'm just really freaked out. I'm leaving for the emergency room now but I just wanted opinions and experiences from others. Thanks