As your uterus begins to expand, you might notice you're constipated. To prevent constipation, try to eat fresh or dried fruit, raw vegetables, and whole grain cereals or breads everyday. Also, try to drink eight to ten glasses of water everyday. Some of these servings can be substituted with fruit or vegetable juice. Try to avoid caffeinated drinks (coffee, tea, colas, and some other sodas), since caffeine makes your body lose fluid and won't help with constipation.