Yes, this can be correct. Sometimes we cannot start collecting payments directly in the month you began exercising. If you pay monthly, this will be corrected on your renewal date: the last month of your fixed term and the first month of the renewal will then be collected in the same month.
Are you unsure if this applies to you? Check the description on your debit. For a 12-month subscription, you will see, for example, that you have paid for period 12 of 12 and period 1 of 12.