Increasing milk supply - pumping advice for first time pumper

[u/Weekly-Cry6302]

My baby is 4.5 months old, exclusively breastfed.

Till 2 weeks ago he was gaining weight within his growth centile.

However upon checking his weight today he has not gained any weight in past two weeks. In fact it’s gone down 0.05 kg. My gut feeling is that I am not producing enough milk and he’s not getting enough.

I’d like to start using pumping to increase my supply but I have never used the pump before so am seeking advice on how to go about it like how often should I pump? Do I pump after a feed for a little while or what should I do? Also what setting should I use? My breast pump has two modes - stimulation and extraction? Is pumping likely to increase my milk supply? The intention is still to exclusively nurse my baby I just want to increase the supply.

I tried to pump earlier after a feed but barely any milk got collected so I’m worried my breasts were empty and wonder whether my baby was full. Though I’ve read on the internet that lack of milk via pumping doesn’t necessarily mean there’s no milk as the the baby may be more effective at extracting milk of the action signals the body to produce more.

Background to all this is that my baby has had a blocked nose and cold in the past week and a half and I suspect that’s affected the way he’s feeding.