I have MS and recently started Lyrica (pregabalin) 50mg one capsule twice daily. This is to help with my pain. Any major side effects to look out for?

Some effects. Common limiting side effects of Lyrica include drowsiness, dizziness, significant weight gain, swelling of feet, sedation, fatigue, etc. You might find success with pain as you increase dosing. You did not list your MS drugs, but a potent agent such as Gilenya or Tysabri (natalizumab) might help with your multiple symptoms as you proceed.
Watch for. Dizziness, sedation, fatigue, vision issues. These are most common.