That's GREAT!!!!
It is totally normal for the milk to stop after a little while. If you keep pumping, it will start back up (that is your second let-down). I always had to pump through at least two letdowns in order to increase my supply. Sometimes that would take me the better part of an hour (I know, I was obsessed with it, but with our difficulties, it was necessary if DD was going to get any breastmilk at all).
some tips that helped me:
try to relax.
take deep belly breaths like you learn in childbirth class.
visualize milk squirting out with each exhale.
think of your milk filling baby's tummy.
you really have to love your pump in order to give it milk - our bodies just aren't designed to feed a plastic machine.
adjust the speed and suction settings on your pump to closely mimic the way your baby nurses. For me this was a faster speed and softer suction. Keep adjusting the speed and suction until you know what works for you. sometimes it helps to either speed up or increase suction after letdown starts.

It is totally normal for the milk to stop after a little while. If you keep pumping, it will start back up (that is your second let-down). I always had to pump through at least two letdowns in order to increase my supply. Sometimes that would take me the better part of an hour (I know, I was obsessed with it, but with our difficulties, it was necessary if DD was going to get any breastmilk at all).
some tips that helped me:
try to relax.
take deep belly breaths like you learn in childbirth class.
visualize milk squirting out with each exhale.
think of your milk filling baby's tummy.
you really have to love your pump in order to give it milk - our bodies just aren't designed to feed a plastic machine.

adjust the speed and suction settings on your pump to closely mimic the way your baby nurses. For me this was a faster speed and softer suction. Keep adjusting the speed and suction until you know what works for you. sometimes it helps to either speed up or increase suction after letdown starts.