I've been nauseated my entire pregnancy, and I've been unable to brush my teeth with toothpaste since about week 10. I've tried different toothpastes, but nothing will work. I throw up everytime I use toothpaste after about 4pm... It's weird. But I've learned to use only water on my tooth brush before bed, and I brush 2 or 3 times in the morning / afternoon with toothpaste. My OB and dentist both said just using water at bedtime is fine. Good Luck.