Girls, hello everyone. I've had milk for three days now. My right breast…

Girls, hello everyone. I've had milk for three days now. My right breast is normal, without pain, but my left one hurts when it starts sucking, then it sucks and becomes better, in feeding again everything is the same. There are no cracks. Has anyone experienced this? What should I do? Should I give this breast more often, or what? After feeding, will this breast be painful from just thinking about it. Inside the nipple hurts.