My ds is 6 weeks and tends to spit up a lot if I overfeed. How long should a feed normally last. He only eats from one side usually. He stops eating after about 5 to 8 min but I can keep offering until 10 min. When I do that he spits up. However, I feel like 5 min is so short so when he cries again after 1.5 to 2 hours I don't know if it's because he's hungry or tired. How long should he be averaging at each meal?