Hi, I am due August 1 but never post :)    I just read this book http://www.amazon.com/Natural-Pregnancy-Book-Nutrition-Holistic/dp/1587611783/ref=sr_1_1?s=books&ie=UTF8&qid=1301338968&sr=1-1 and the author writes to suck on Thayer's Slippery Elm lozenges.  I found them at Whole Foods for cheap and I think they work ok, but not as much as Tums for me.  They do help me cut way back on Tums though... hope that helps because I know heartburn sucks.