J.K.
The only way to increase your milk supply is to nurse your baby. For me pumping is only good for releasing engorgement when I am away from my baby. Make sure baby empties both breasts before giving any formula. Then only give a small amount to top off so it doesnt effect the next feeding. At 4 weeks old baby should be nursing every 1-2 hours so I will seem like all day constantly. When baby needs more than you are making they cluster feed, which means they switch from breast to breast without a break, during growth spurts, my baby once went for about 4 hours a stretch for 3 days until my milk increased to meet his needs.
Keep nursing, put the pump away and just count wet diapers instead. Your baby is much better at getting milk out than a pump. Talk to a lactation consultant or there are some good groups on Facebook, the leaky boob, respect the breast, la leche, are just some of the support groups on facebook. I.would check them out for breastfeeding advice.