pumping

trying to get a good stash for when i go back to work just in case pumping becomes to hard to do at work, but when do you guys pump? i want to pump right after breastfeeding him but i spend 20 min sometimes burping him, sometimes he’ll poop so i have to change him, and if i put him down too soon he cries 🙄 he sleeps but i have to wait for him to be in a deep enough sleep for me to put him to bed and it’s almost 45 min after i fed. does that matter? i just feel like that doesn’t give me enough time to i guess refill back up when he feeds every 2 hours sometimes. i haven’t been pumping for that reason alone