Milk Supply and pumping

Danielle • Dated my husband since December 2006 and we were married May 2016. Baby boy Henry born June 2nd 2017 👶🏼💙
Is it normal to not be able to pump a lot at 1.5 weeks postpartum? My baby is gaining weight and wetting/pooping diapers well but anytime I pump I usually can't get more than 1-2 ounce between both breasts. I try to pump 1-3 times a day but it's hard because I am also feeding my baby all day and my breasts get sore from the pump. I want to start building up my freezer milk supply for when I go beck to work in 2 months, I only have about 15 ounces frozen right now total. Should I be pumping more often?