Burning sensation, 7 weeks after explant. Is this normal?

Burning pain after any surgery is typically nerve pain. As the nerves regrow and establish connections, burning pains, occasional sharp pain, and itching are common. Also you may have pulled something or strained something when you lifted your son. I would recommend that you rest and relax over the weekend. You could also take Ibuprofen and ice the area intermittently to decrease any swelling present. 

Did you get a lift with you explant? Did you have capsulectomy with your explant? Both of these maneuvers may lead to cutting of sensory nerves that are growing back. This usually happens after 6 weeks.