Ulnar sided wrist pain on lifting weights?

See a hand doctor: Many causes for pain. Tendon or muscle tear, carpal tunnel syndrome, etc. If is recurring see and hand and arm specialist before you continue this exercise!

Impingement: This could be a due to a variety of conditions ranging from a simple strain or sprain or could be indicative of nerve, cartilage or bone injury. I would advise evaluation by a hand surgeon if this persists beyond 7-10 days for an exam and diagnostic imaging for such conditions as tfcc cartilage tear or ulnar plus variance, etc.