I believe your GP may continue to prescribe it.. your case sounds like this:
Prevention of recurrent venous thromboembolism
Treatment Phase: Continuing treatment
Clinical criteria:
Patient must have a history of venous thromboembolism.
I am sure your GP wouldn't prescribe it otherwise
GP can prescribe it for whatever they feel like, including headaches/coughs/colds or other such nonsense. (This medication is not for any of those but I've seen quacks prescribe all sorts for crazy reasons. They are often the ones who charge the most).
The PBS will only fund it for that indication with the appropriate streamlined code, however, and most other uses will be off label and need to be appropriately discussed with the patient.