Re: Do I need to pump?
Welcome to the forum and congratulations on the new baby!
If your child is 4 lbs past his birth weight at 5 weeks of age, there is nothing wrong with your supply. Babies are supposed to be back at birthweight by 2 weeks, and then start gaining consistently. Average weight gain in the 0-4 month age range is around 5-8 oz per week, and your child has gained significantly more than that. So put the idea of a supply problem out of your mind! Soft breasts mean nothing when weight gain and diaper output are good.
Next, take the formula and put it in the trash or donate it to a needy family. Again, you do not have a supply problem! Your baby ate a large amount from the bottle because that is what babies do when given bottles. When a baby feeds from the breast, milk flow slows or stops when the baby transitions from sucking eagerly for nutrition to sucking gently for comfort. When a baby feeds from a bottle, the bottle delivers the same fast flow regardless of how the baby is sucking, and the baby must keep swallowing or he will choke. This is one reason why bottle-fed babies are often overfed. Not knowing better, I once fed my newborn 7 oz from the bottle- which she then proceeded to puke up!
Since your baby's weight gain is above average, he's feeding faster than average, spit-up is frequent and voluminous, and he often wants to feed from just one breast at a time, there's a good chance that you have some excess supply going on right now. When mom has high supply, letdowns are often fast and that can cause more fussiness than average. But even when letdowns are not too fast, babies are often increasingly fussy in the late afternoons/evenings. The best thing to do when evening fussiness strikes is to nurse through it, if baby is willing.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"