3 weeks is right around one of the common growth spurt ages, it is usually better to wait to introduce the fake nipple until 4-6 weeks to allow supply to be adjusted to what baby actually needs. anothe rbig one usually happens right around 6 wks old. re- the ped saying it was a god time; maybe she needs a bit of an update/refresher/reminder? then again, MOST peds know very little about bf to begin with.

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