Health insurance (Sydney)

Hi,
My husband and I have lived in Sydney for the past 14 months. We have a private health insurance, with no medicare. As part of my visa, I need to subscribe to an overseas visitors health insurance.
I just found out that I need some health services that are not part of my cover. I tried to have a look on other health insurance but will have to go trough the whole 12 months waiting period to be able to claim for that service.
I have seen a local health insurance (not for overseas visitors) that have a 2 months waiting period for this kind of service.

For sure I will switch to another insurance asap, to ensure after the twelve months period this service is included. But in the meantime am I able to contract two different health insurances?
Thanks for your answers !