My supply didn't drop after I went back to work, and that was because I was fortunate enough to have the privacy to pump 3 times at work, 10am, 1.30pm, and 5pm. I'm yielding around 1.5litre as an exclusive pumper, 7 times a day, now dropped to 6 coz 7 is too much after starting work. Am nearing 5mths pp.