Yes it is illegal here in india to determine the sex of your child. But it is not your fault either that you MAY give birth to a girl child. Your husband has a big role in sex determination. He is the one that carries the X and Y chromosome that determines the sex of the child. So why are you worried. In fact you should tell him that he is the one who determines the sex of the child and if it is a girl it is not your fault and neither his acutally but if he were to blame he would have to blame himself.
There are many ways that you can enhance your chances of conceiving a girl or a boy. Please serch on the net.