I've always used tums with all of my pregnancys. Helped a lot. Also avoid hot, spicy foods, which I love so easier said than done. Also try drinking cold milk. Helps with the acid. I had acid reflux before pregnancy but I refuce to take any meds like that while preggo.
Don't take tums they are essentially just baking soda and just release the gas they don't prevent it. My OB has them on the not allowed list because side effect can cause major issues.
I used Prilosec and it worked wonderful, only thing I don't like was I had to keep taking it daily. Until my Ella dropped and my heartburn went away.
Call your OB/midwife and ask what brand they recommend. Also the cold milk really does work well.