If you've been sidelined by a headache, a cold compress and a solid nap often does the trick. But if you need additional relief, it's important to choose your pain medication wisely. Acetaminophen (the main ingredient in Tylenol) is safe for moms-to-be when used as directed. However, you should avoid aspirin and ibuprofen (found in Advil, Motrin, and Nuprin). Studies have suggested that taking these medications near conception or in early pregnancy may increase your risk of miscarriage and birth defects.