You thinking you may have torn a ligament and actually tearing one are two different thing. You should go to the doctors and get checked out on the off chance you sustained a hairline fracture somewhere or broke something, it is possible to have a break or a fracture and still be able to use it. (I broke my right wrist years back and didn't even know it until I had to get X-rays the following year for an unrelated incident) But if it is a torn ligament the doctor will have you wear a cast or splint over the area an tell you to be careful.
A torn ligament is a bad sign and therefore needs urgent medical attention. You may have torn it by lifting a heavy object, taking a bad fall or a sprain. Some threads on the ligament are over stretched and torn resulting in inflammation and pan. Visit diagnose-me.com