While ever the child is a feotus (aka unborn), the baby has no rights of its own because it is not identified as a legal person. As such, you have no legal obligation to inform the father of his parentage or your location.
If you wish, you can leave the father off the birth certificate, but doing so will forfeit your entitlement to receiving child support from him.
Once the child is born, he/she will have a legal right to know, spend time and communicate with each of his/her parents on a regular basis, under section 60B of the Family Law Act 1975. As such, if the father finds out about the child, you may face proceedings for parenting orders that enable the child to spend time with the father. If left off the birth certificate, this would likely also include some proceedings for declaration of parentage.
In short, at the moment, there are no legal obligations on you to inform the father of his parentage. Once born, the child has a right to know, spend time and communicate with both parents on a regular basis, but it's the parent's responsibility to seek that such a right is upheld, which places the onus on the father to pursue proceedings. Excluding the father can be a gamble, especially if things end up in court, as the court may question your capacity to support and encourage your child's right to have a relationship with the father.
However right now, you are not obligated to inform the father of parentage, nor of your location.
I hope this helps.