Pregnancy Weekly Guide
[Week 17 Mother] Oh, the heartburn!
As the fetus grows, the position of the stomach and intestines changes.
You may experience sour stomach or heartburn because the position of your 'stomach' has changed, the sphincter in your esophagus that prevents acid from refluxing weakens during pregnancy, and the pressure in your 'stomach' is higher when you're pregnant.
If the symptoms are too severe and bother you a lot, talk to your doctor - medication may be available.