During the third trimester of your pregnancy, your breasts will start discharging a yellowish, thin milky liquid which is called the colostrum. This is your body’s way of preparing you for breastfeeding. It might start as a drop but the flow can also becomes more. You can use some nursing pads (cotton pads for breasts) that are easily available in the market. There is nothing to worry in it as this yellowish milk is really healthy for your baby. It contains antibodies that help fight infection and strengthen the baby's immunity system.