Hi! Welcome to BB
I live in Baldivis, so not far away from you. I know that there's an ABC on Safety Bay Road. Though I haven't got my DS in day care and don't plan on it for a while, I have been looking around for when I do plan on doing it, even for just (like yourself) one or two days a week (more for his social 'life' per say)
Let me know if you find any - As I said to someone before, Google is your best friend if you don't get many replies