Maternity leave question- Canada

Hey guys!

I’ve been thinking lots about when i should be planning my maternity leave to start. I know it’s early, i don’t have to submit my LOA forms until May i think. Since I’m due June 21. My question is, how soon before your due date should you stop working/ start maternity leave? In Saskatchewan where i live, i think you can start mat leave up to 12 weeks before your due date. I was thinking I’d try to work until maybe the week before I’m due. Is this unrealistic? When did you stop working?