Second Trimester During your second trimester (13th to 26th weeks), your baby will grow to 14 inches and weigh about 1.5 pounds. Your baby's eyelashes and fingernails are growing. In addition, you will begin to feel the baby move at about 16-20 weeks of pregnancy, which is called quickening. You can hear the baby's heart beating with an electronic monitor or stethoscope. Its heart beat will be approximately twice as fast as yours. During this time, you will be outgrowing your clothes, the skin on your stomach begins to stretch, and your nipples may darken and leak a yellow fuid called colostrum, which is present at birth. Nutrition and Exercise Try to have a caloric intake of 2500 calories/day Maintain a well balanced diet with plenty of fiber Take prenatal vitamins if prescribed Avoid the use of alcohol and tobacco Modify your exercise regimen if needed to protect weight bearing joints, back and abdominal muscles Be careful with lifting and carrying heavy things.