Supply of milk

My lo is 2 weeks old and I'm exclusively breast feeding her. Trying my best. Today is her 2nd week check up. Hopefully she's gained some weight that they don't recommend me for formula. I seriously don't want to substitute. But I'm not sure if I'm doing the right thing. Most of the time my breast feels soft. I wonder if my lo really gets some from it. I haven't pumped so far. My LC asked not to pump until 3 weeks. Should I? Pleas help.