I think you would be fine. People don't smoke weed at concerts anymore usually there are police. I'm sure your not going to swag. So I would just be careful and I'm sure you will be fine !
I went to shows and dance nights all through my pregnancy with my son - if it was super loud I'd stay back from the speakers but you can't smoke indoors here so that was never a problem. I got to see a lot of good music and take advantage of the last several months before we needed to get a babysitter.
I went to one when I was 8 months just don't go down on the floor
Or potentially getting hit in the tummy. I don't think there's anything wrong with going but be careful of the second hand smoke and people bumping around.
That's really not band for the baby. But all the weed and cigarette smoke. Could be. I wouldn't risk it