You also have options on how you would like to receive your payments you can receive all fortnightly. FTB A a minimum rate and the rest paid when you lodge your Tax Return, you can elect to not receive part B until then end of the fin year.
We did this instead of getting fortnightly payments, for both A & B and we found it to work really well for our situation. If we had gotten it fortnightly, it would've been spent, but by getting it in a lump sum, we actually got just shy of $6000 so we've been able to save it. Totally off the track, but thought I'd put it out there