Yes there are a number of herbs (galactagogues) that increase breast milk supply safely and effectively.
Fenugreek: capsules should be taken 3x’s per day
Blessed Thistle: should be taken WITH Fenugreek
If you are pumping, you must pump at least 8 to 12 times per day to increase flow.
Massage your breast in quadrants while you’re pumping.
Avoid long stretches of uninterrupted vacuum
There is a FABULOUS book Called
Wise Woman Herbal for the Childbearing Year that explains a number of solutions to the issue you’re experiencing. Including other herb combinations to take to increase flow. Your local library may have a copy of it, if not, it’s well worth the $8 online.
Congrats on your new baby!