No i dont. The extremely loud music will make the water that the unborn baby is in react un noticably to you, but it will be uncomfortable for the baby.
I think that it would be perfectly fine to attend a rock concert, as long as you are careful. You don't want to have PIT area tickets because of the pushing that could go on, so try to get actual seats.
It depends on the group. Does it attract a rowdy crowd likely to stomp over a pregnant woman?
For that matter, is it safe for anyone to attend this rock concert??