It's funny the differences in how many scans people have. As everyone's said it's up to your GP/Ob. I have had 4 scans so far and have all covered by medicare.

1st was a dating u/s cause I had irregular periods and no way of knowing how far along I was.

2nd was at 12w. I'd had some spotting and so they sent me for an u/s to check everything was ok. However my GP had given me a refferal for a scan at 12w to make sure everything was going ok.

3rd was my morph scan

4th was because they couldn't get clear pics of the heart at the morph scan so had to have another one. Which worked out good cause both my mum and dad got to come to an u/s each.

5th will be between 34-36w. This one was requested by me as my hubby has been overseas since my first u/s and I wanted him to be able to come to an u/s before the birth. Ob is happy to refer me for one as he can use it as an opportunity to check Peanuts position etc prior to delivery.

My best advice is just ask. Most GP's/Obs are happy to give you a refferal for an u/s when you request it