For the last two nights, when I wake up for middle of night feeding (after 5-6 hours) my left breast is hard and large and my right breast is softer and smaller. My daughter still gets milk from it, but I'm worried the supply might be dwindling there. What could cause that and how do I handle it? I switch the starting breast with each feeding, but she usually drinks well from both. Also, I pumped both sides right after the 9 p.m. feeding.