This message is for the woman who is pregnant and has a bad after taste, or bad tasting burp.... Are you taking prenatal vitamins? This happened to me during my last pregnancy and it was the brand of prenatal vitamins I was taking. I had a terrible, sickening taste in my mouth when I would burp. (I hope this doesn't offend anyone, but it really is true) My doctor changed the brand of prenatal vitamins I was taking, and the bad taste went away. I hope this helps.