Breastfeeding question

B17
My son is 3 weeks old. He usually eats about 10 mins on average each feed. I alternate breasts for every Feed. Question #1 lets say he eats at 8:00 for 10 minutes on left breast and then wants to eat again at 8:40... Do i put hin back on the left? Or do i give him the right? Also is this considered 2 different feedings??thanks!!