This depends on whether you are signed up for the Hubpages earnings program or just through Google.
If you are on the Hubpages earning program then they pay you through Paypal once your earnings go over the minimum threshold, so you need to associate a Paypal account to your Hubpages account. Until they go over that amount you do not get paid. Once you go over the amount, then the payment needs to be processed and then sent. So it is not instant when going over the threshold. Will take a few weeks.
If you are using Google, then your payment comes from Google directly. Google pays into your bank account so you need to ensure you have verified your account with Google and provided them with bank details. Google also has a minimum threshold your earnings need to go over in order to get the payment.
They pay on a particular day each month, but only if you have gone over the threshold, otherwise the amount will be carried over to the next month and accumulate until you reach the minimum.
Even when you go over the minimum threshold, you still need to wait until it reaches the payment day, which is the same day every month.