I wouldn't. Anything can happen, someone could easily fall into you or well.. anything really. I'd personally just wait (:
My friend went to an outdoor all day festival when she was 34 weeks. I'm 38 weeks and I just went to a concert last wekeend. Just be aware of your surroundings, if it's music that pwople tend to get crazy to don't go into the crowd, enjoy from a far.
It's the Garth Brooks concert so I don't think it'll be too bad
A gath brooks concert should be fine id say go and enjoy it and just listen to your body if somthing dosent feel right head home.
If you're not standing in the crowd, I would think it is fine. I went to a concert at 16ish weeks pregnant. I wasn't showing yet, and I was in the floor, but I also had three people protecting me..lol I was fine though. At that far along I would probably go as long as I had seats. :)
I went to a slipknot concert this past weekend i was in the seats thoughi didnt go to the pit im 28 weeks the sitting and standing might get to you though it did me.