This depends greatly on your size and your activity level. Check with your doctor to be sure you are eating the right number of calories for the two of you!
The phrase "eating for two" applies to pregnant women for a reason. You should not limit your caloric intake so drastically while you are pregnant; it could hurt your child.
1500 calories is too little and you will run the risk of becoming tired or having a baby who grows slower. You need about 2000 - 2500 calories when pregnant.
1500 calories is a very small amount for any individual of an "average" size to consume per day. When pregnant, a mother needs to increase her food consumption in order to stay healthy while the baby is growing.
