no, he is not going to take anything from your bones. you may have a dip in milk that will last most of the pregnancy, or the first trimester. I have a very forceful toddler who does not like to take no for an answer for nursing. I do say no, but i know how hard it is. Try cuddling, sippy of milk or some other beverage, food, more interaction (ie, is it boredom?), don't sit down.