Hello Evelyn, The pulsation you are feeling just above your umbilicus (Belly button) is from your abdominal aorta. This is the main blood vessel from the heart which takes the blood to the abdomen and the lower limbs. When you are stressed, your adrenaline level is high and this causes the heart to beat faster and harder pumping more blood into the aorta. This is normal. If it is present at times when you are not stressed or the size is increasing then you may do an ultrasound examination of the abdomen to make sure that there is no dilatation of the abdominal aorta. If you have further queries, I am available to answer them. Dr. Noble Zachariah