Hi,
This is a nice article. Just would like to add few more things that we should be little more cautions while exercising that it should not be increase your heart rate and feel heavy breath as it would lead to decrease in blood supply to your baby so do very light exercises. And if you have any discomfort, chest pain, etc, immediately contact your doctor. Ans make sure that after 5 th month of your pregnancy, try avoiding any exercise done by sleeping on your back.