All of the following are definitive signs of pregnancy, EXCEPT:

The abrupt cessation of menstruation in a healthy reproductive-aged woman who previously has experienced spontaneous, cyclical, predictable menses is highly suggestive of pregnancy. But there is appreciable variation in the length of the ovarian--and thus menstrual--cycle among women, and even in the same woman. Thus, amenorrhea is not a reliable indication of pregnancy until 10 days or more after expected menses onset. Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 8. Prenatal Care. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.