Usually preferential discounts is for new customers (one of my pet hates and loyalty should be rewarded the same or even better).
Give the NOW Broadband Team a phone call when you are around 2 weeks before the twelve months are up to see if you can renegotiate a better deal than you are currently on.
How many years have you been with NOW Broadband ?
If it's the first year then go to My Broadband & Calls and under Orders & Appointments your live activation date would be the start of the 12 month contract.
if it has been longer, then go to My Broadband & Calls again and under Messages see if any of the recent messages relates to renewing your Broadband contract.
Otherwise you will have to search for any old NOW emails on whatever email service you use.
Most of the time (not always from what i have seen) within two to four weeks NOW will usually notifying their Broadband customers that they are coming up to the 12 months and will give you a number of options on what to do next.