Yes, ginger tea would be excellent also but not as good as sage. Make yourself some ginger tea. Place a cup of water in a pan and add 1 t. of ginger powder and bring to boil. Let set for twenty minutes and then drink. The capsules are not as good.
Ginger is an anti inflamatory. There is no reason for your stomach to be upset from what you describe other than a virus going around or that you are pregnant, lol. One day of fasting should make you extremely weak and tired but not as long as this unless your immunity is extremely low. Make sure you place a hot water bottle on your stomach to ease the pain or a hot pad. This will ease the pain. Never keep on your stomach for more than 10-15 minutes at a time. Rest and then do it again.
Never begin a fast when you are sick. You must get over your illness before you can fast again.