When to start pumping

Guess • 🔹Married to my high school sweet heart🔹Mom of three amazing boys, Maverick born Jan 2017, Arius born Sept 2018, and Draxton born Aug 2021

With my first I had to start pumping at like 3-4 weeks pp to get a supply built up for when I returned to work at 6 weeks. This baby I am taking the full 12 weeks. When is a good time to start pumping?