Heartburn

Any advice on heartburn. With my first 2 children I never had it, but with this pregnancy it seems constant and tums are just not cutting it. I took some alkaseltzer chews and they seemed to work but my doctor advised against them or taking to many of them since they have aspirin in the ingredients. I have cut back on all the spicy foods and tried not to eat late or heavy. Does anyone have something that works for you personally or know a remedy that worked for someone else. Thanks in advance