Hi mommies, I've some question to ask. Need advise. 1) How often should formula fed babies poop ? My LO don't poop daily, isit something to worry about ? 2) My LO currently switch from NAN HA to NAN optipro and I realize she spits up a lot after fed, any other milk recommend to reduce spit ? Or should I change back to NAN HA ? 3)How much weight should baby gain per week ? Thanks in advance.