depending on your award you can generally start leave earlier. you can ask your HR department though. they may have something in place that says you can use the normal rec leave for first four weeks (which puts you up to the "normal" time for starting mat leave) and still get your 52 weeks from that point, not the point you start your rec leave (so 52 weeks from your 36 week mark, not your 32week mark if that makes sense)

a fair amount of what is in the OP on this thread is now obsolete - when i have a chance i'll try and update the c'link side of it if i can