How can you tell if im having a boy or girl?

Usually, babies are born at the hospital. There, they have a machine on one of the floors. After the nurse or doctor is finished using it, she will tell you if your baby will live as a boy, or a girl. You don't have to wait for the nurses or doctors or even the immediate delivery results to tell if the baby is a boy or a girl. Ultrasounds should be able to tell, eventually, if the child is a boy or a girl, as boys have something a little more obvious between their legs than what girls are idenfied by as infants and new borns. hi l had a boy in my first pregnancy and l was only sick once and l had no problems through my pregnancy,now lm seven weeks pregnant l feel constantly sick all the time lm getting backaches terribly,how do you know when you are having a boy or a girl can any one help me thank you