okay, so i have been exclusively bf'ing my 4 week old daughter. now, i have been trying to get a supply of milk so that i can go out every now and again but am having trouble. i was told to pump right after feeding her, so i've tried but i don't get anything. i drink a full glass of water before and during bf'ing and pumping, i'm relaxed but i still don't get anything. when does everyone else pump? any suugestions?