I was pumping last week at daytime as i'll be back to work soon. The first 2 days i still able to meet bb demand. He took 4oz every 2.5 to 3 hr. But later on, the supply was dropping. Sometime i cant even get a drop, even though hand pump. I got very scare & start to burse him directly. Now he refuse to use bottle again & my supply don't seem to be enough when i start pumping. How?