You don't say what kind of pain, or where it is located. If it is bad enough or doesn't go away on its own, you should see your doctor, even if it wasn't caused by trauma such as a fall or vehicle collision. Your doctor will probably refer you to an orthopedist.
I have pain L2 through S2, and yoga has helped more than anything else. Lower back pain, especially in the Lumbar region is extremely common, especially starting in middle age. You're in your 60s, so some temporary pain is to be expected. Spinal disc degeneration is part of the aging process, and you should probably be tested for osteoporosis.