I wasn't with Monash IVF, but at my clinic did a natural FET. I had the trigger injection and was put on progesterone support. After BFP I had to continue taking the progesterone pessaries till week 10 or so as the levels were low according to the blood test. I was on crinone with the first IVF cycle and the following fresh transfer.
I'd definitely be giving them a call!
Good luck, am keeping my fingers, knees and toes crossed for you!! And am quietly stalking!