Yes tums! Just a caution not to scare you but i am going to share my "heartburn" experience. I thought i had crazy heartburn to the point i was having trouble breathing so i went to emerge and it turned out i have a gallstone and was having a gallbladder attack. If i was not pregnant i would have had surgery to remove my gallbladder the same day. The pain was similiar to heartburn, burning sensation except it didn't rise above my breast bone. It was excruiating. I felt stupid thinking it was only heartburn when it was something much more serious. Again i dony say this to scare you but i wish i had known the symptoms of a gallstone are similiar to heartburn and gallstones are more common in pregnant women who have had previous pregnancies as your organs shift to make room for baby.
I have bad heartburn as well. I've been taking tums and drinking milk. The milk helps me more than anything.
My Dr says tums are the safest option !