Waiting to pump?

britney
I was told to wait four weeks after birth to pump. Is this what everyone else is doing or did anyone pump sooner. I am 3 days post delivery. I am nursing every two hours or so. They had told me to try to do 20 on each side but my daughter is done after about five to ten on each side. I really try and make her go longer but she passes out or stops sucking. I was nervous she wasn't getting enough when she was feeding so I pumped after she was done last night for ten minutes and got about an ounce and a half. I pumped again today for about five minutes after she fed and got almost two ounces. I feel like if I don't pump my boobs are going to explode. They leak so much if I don't pump and I feel like it's going to waste.