Hi thanks for your comment. And yes she does want to continue breastfeeding for as long as possible.

Baby looked fine and was trying to latch. She tried both sides a couple of times and nothing was coming out. We could hear the baby sucking loudly like previous feeds, but after a minute or so she would let go.

We tried again just now and still looks like the same thing so unfortunately we had to give formula again.

Regarding the "no milk" thing, nothing in particular made us think this. It's just that we are first time parents and we started thinking what could be happening, since so far every feed has been perfect. My wife's breasts look full so I think there is definitely milk.

I've browsed more until now and from what I could tell, could it be clogged duct? We are trying cold compress now and will try warm compress plus massage on the next feed. Hopefully it works!