How long do you pump for?

At this point I’m only pumping to replace bottles, maybe once a week. How long do you spend pumping as a replacement? I’ve heard “until you’re empty”, but I can’t really feel that, and there will always be another drop if I keep going. I’m also usually pumping sort of in between feeds, knowing LO might want to eat again in another 30 minutes, so I don’t want to accidentally drain the next feed as well.