The brake pads and shoes are not the parts that fail suddenly and cause problems, it is the hydraulic system that is the culprit when you have a sudden brake failure. Since your car was built after 1967, when the Federal government mandated a dual braking system, it is unlikely that you would have a catastrophic failure of both braking systems in your car. It is wise to have the system checked, and the most important part is the brake lines themselves. If they are rusted on the outside, they should be visually checked for defects. One thing that you can do is while the car is sitting in your driveway, push on the brake pedal as hard as you can. If a brake line is likely to fail, it will most likely fail when you perform this test. It isn't during normal braking that a line fails, but when you hit the brake pedal quickly and very hard. This builds up a sudden and high pressure condition in the hydraulic system, and if there are any "weak" parts, the sudden high pressure will cause them to fail. Usually if a brake cylinder or caliper is failing, you will see leakage of hydraulic brake fluid running down from it. Hope that this helps you.
Paul