Actually, no - now that you mention it, they haven't. They usually send out an email early-ish in the month saying something like 'Your £xxx commission will be processed by the finance team on [some date] and you should expect payment the week of [some other date]'.
I didn't get one of these this month (it's quite possible I didn't earn any commission - I try not to look at stats) but if you did and you still haven't had your commission, chase them up.