Breastfeeding Newborns

Cassandra
Hello January moms! 
I had my daughter one week ago today 01.17.17 at 39 weeks. The nurses in the hospital were great and showed me a lot in terms of breastfeeding. However, my baby keeps losing weight. We go back Thursday for another checkup and I want to make sure she is good. She didn't really lose any weight in the hospital, but has lost a pound since being home. 
The doctor is worried, but said he does not want her to go down anymore. My milk without any colostrum came in yesterday. My question to you all is when you initially started pumping, how many ounces were you/ are you producing? 
I REALLY do not want to put my daughter on formula and will do whatever needed to ensure she can be breastfed and have breast milk. Please help!!