If milk makes you sick then do not drink it. Milk is rich in calcium and that is why it is recommended that pregnant women drink so much milk. There are many other foods and drinks that are rich in calcium, like cheese, yogurt, fortified juices. You should discuss this with your health care provider, he/she may want you to take an extra calcium supplement in the place of drinking milk to ensure that you get a sufficient amount. Drinking milk doesn't have anything to do with your milk supple for your baby, but it is necessary that you drink plenty of fluids when you breastfeed.