If you are near an unpaved road, you will likely need to change your filter every month due to the amount of dust flying through the air. If you have pets with fur, you’ll also want to change it every month, as pet hair clogs up your filter pretty quickly.
The same goes if you, or someone in your home, has allergies of any sort; you’ll want to change it monthly to stay on top of eliminating the allergens in the air inside your home. If none of those apply to you, you should at least check it monthly, but you might have to replace it bi-monthly.