Prospective Marriage Approval

I'm new to the forum but a seasoned pro at looking up forums for advice, tips and tricks when it comes to immigrating to Australia.

My partner and I have been doing the whole "long-distance" between Canada and Australia (Me mainly going to Oz) for over 2 years now. I lived with him there for about a year but had to come back as my Working-Holiday Visa was nearly expired. We had talked about marriage but the realization that we HAD to get married didn't hit us till about a month before my departure. We decided to go the prospective marriage route and are planning a wedding over in Melbourne for next year. My problem being that I applied quite late for the P.M. visa (I came home at the end of June but didn't end up filing till end of September), all evidence and application were ready, but our letter from our marriage celerant was stuck in customs...A LETTER!!

Anyways, I'm suppose to go back on January 8th and so stressed that my visa won't be approved before I go. Has anyone done or known about someone who's gone over before an application was approved and just got married, applied for a spousal visa within the country and everything worked out? Love reading about other people's experience, just gives me an idea as to what to expect.

Thank you!