New to pumping

alge44

I am EBF my LO who is 3.5 weeks old. I tried pumping today to start to build up a stash for when I go back to work and for ooutings. I pumped after the first feed of the day and didn't even get an ounce. Is that worth saving? Should I pump after every feed for the first few days? From what I've read, I should be able to get more out over time, right? TIA!