Hi Maddie,
It takes your body some time, days to a couple weeks to really start building up milk that is significant. Unlike when you give birth to a child and your milk "comes in", we have to build it up over time by telling our bodies we need it (through nipple stimulation). I know it can seem like a defeating process at times but hang in there. Try to manually express after each pumping session. In the beginning, I got more from manual expression than I did the pump, although the pump is still needed for the stimulation. I got my first sprays through manual expression. At the end of the day we need to "drain" our breasts and that is what tells our bodies we need more. Hang in there, I know how you feel
