S.,
Congrats on BFing! Since you are a nurse, do you have access to a group of lactaction consultants when you return to work?
Just to add my experience, I was not able to pump very well either for the 12 weeks I was on maternity leave and nursing on demand. But as soon as I went back to work and actually *missed* a feeding ... viola! I was able to pump enough to store for the next day's bottles while my son was in daycare.
It's tough; I know! We managed to keep this up for a full year until I could change him over to whole milk. I was thrilled to bypass the expense of formula altogether!
As a nurse, your work schedule may not allow for the consistent breaks needed to maintain pumping at work, but it's certainly worth a try if that's what you want to do! By the way, I used a Medella Pump in Style and loved it.
If pumping at work is just not possible, your body will adjust to the BFing schedule that you and your son move to. It will likely take a few days. You may have some soreness (like engorement, sort of, but not that bad) and leaking, so wear breast pads. It's amazing how nature handles things things.
I wish you the best. Congrats again. And kudos for making the sacrifices it takes to BF successfully. Lucky baby boy!
J.