Its usually at its worse around the third
trimester and pretty noticeable in your
first trimester. Talk to your OB about what may be safe to use on your pregnancy. In general, Tums are generally considered safe in pregnancy. Although they may not work for very long periods of time but your OB can recommend a medication that better suits your pregnancy. I had horrible heartburn in my last pregnancy, I would literally choke on pure acid (very gross, I know!) But after I delivered..