Answer: Going to a concert every once in a while is fine while you are pregnant, but it is not recommended by most doctors. The reasoning for this is that 22-week old fetuses are developing an essential part of the ear called the cochlea, and it can be damaged easily.
Another reason to avoid loud concerts is that thumping music can cause your body to release a stress hormone. The hormone also causes a response in your little one that is not necessarily harmful but not ideal.
In short, you can go to a concert or two during your pregnancy. Just try to keep it mellow.