Medela has a new breast pump that is for mothers of Preemie babies. It has been a huge break thru in increasing the milk supplies of mothers who are breast pump dependent, just as we are in inducing lactation for babies we do not have in our arms yet. It is the "Medela Symphony Preemie+ Breast Pump"
It is not the Regular Symphony but I hear if you have the regular Medela Symphony, Medela does sell a new "Preemie+ sim card", that will fit in the regular Symphony and simulate this new pattern. Here is a link with the whole story and the studies preformed proving the huge milk increase.

http://www.consciousnessawakened.com/pdfs/preemie-brochure.pdf

When I talked to Medela they said you continue to use the Preemie card until you have achieved milk expression of 20 to 40 ml, in at least 5 consecutive pumping's. Then after you have achieved this amount, then you are ready to switch to the 2.0 card.
This breast pump is worth looking into, even to rent for a few months until your milk supply gets up to where you would like it to be.