Milk supply decreased?


I am 2.5 weeks PP and I am breastfeeding and pumping. I don’t have a specific pumping schedule. I mostly pump an hour or so after feeding, but not consistently. I also pump shortly after I feed my baby with a bottle to maintain supply. However, today my milk supply seems significantly lower. I used to get 4oz out of each breast in the evenings and today I’ve inly gotten 1.5-3oz per pump. Did I do something wrong? I’m a little worried!