My lo is 5wks old. For the last week or probably more she has been "cluster feeding" at night. This usually happens through a 4-5hr period starting about 8pm. I am bfing and then pumping (to build up stock for when i go back to work). She will spend about 45min on and off the breast, usually fussing... Then for the next couple of hours cry and demand more(at this time she can pound 4-6oz of the stock i built up throughout the day). She can sometimes spit up and need more burping at this time. Is it normal for babies to be very fussy and cluster feed at night?