I know you are looking for answers from others in Australia mostly but I have had 2 with one on the way and have had different experiences with all three...what I have heard and experienced as normal is that you have your first ultrasound to confirm pregnancy and heart beat and safe positioning of the baby (making sure it's not in your tubes and such) then the next time they do one is anywhere between 17 to 24 weeks, at that time is when they can more clearly check for things such as spina bifida and other visual defects and you can also choose to find out the sex of your baby but you don;t have to...we are not this time...at that point they don't really have need to do more ultra sounds unless they have concerns, with my kids I have had many more ultrasounds than that because of complications, I have a heart shaped uterus and I carry the baby sideways, they do an ultrasound to check the positioning of the baby before and after they flip the baby to make sure the cord is not strangling the baby and that they are putting the head down not the bottom...I also had more ultrasounds in the beginning of this pregnancy because when they checked for a heartbeat and positioning both were bad, no heartbeat and the baby was caught in a dangerous place, by the time I went to the radiologist the baby had moved and had a visible heartbeat...I love seeing the baby on ultrasound but you can truly count it a blessing to not have a need to, it just means that your doctor is fine with how your pregnancy is progressing and that he/she has no major concerns...most of the time when you get your ultrasound at mid way through 17-24 weeks along they have you bring a video tape and you can record it, watching it when you are lonesome for your baby can help pass the time and make up for not seeing him/her until birth...I am not sure how much it differs from the US to AUS but that is how my experiences have been...I hope this helps...Love Meg