And your preggo? Eek. I'm so sorry!!! I'm no doc,. but I have all those symptoms as well...I've heard of SO many preggo ladies getting Costo. The only solid advice I can offer is to eat as organic/vegan/healthy as you can and see how you do.
My own amateur opinion is that lots of GI/liver issues happen during pregnancy, so costo results pretty often.
I'd try to get a diagnoses and then go from there. I'd call around to Dr. Offices and find one who is comfortable diagnosing this condition...don't be afraid to be aggressive in getting the nurses on the phone so they can see if their Dr. can diagnose it... (lots of dr. have no clue what this is- so you don't want to waste precious time/money...)