Sorry youre feeling this hun.

Only thing i can add is, maybe whatever it is, if it is IBS.. its flaring up while youre pregnant because you have alot lower immune system during that time and bubs is sucking all of your good levels away iykwim.
Im normally a target when it comes to mozzies, but whenever pregnant if i get bitten, they turn into large dark red bubble welts and sometimes get infected. Doctors have said its because i have a lot lower immune system to fight anything off. So maybe whatever it is is the same for you.

Havent really given you any answers as to what it is, but maybe why it is.
Hope can figure it out