If you are not getting let down try the pump on a lower suction but quite fast to
start with until you feel the let down of milk
, also try hot wash cloths on your breast
and have pictures of you babies near by, perhaps even an item of clothing or a blanket that has been against them that you could smell, or even a tape recording of their crying ( it all sounds weird I know but it does help honestly). Once you get let down slow the pump down a bit but increase the suction.