First day back at work and pumping next to nothing...

heyitsme

I usually pump 3-4oz (total) in the morning when I pump at home (I only have 1 functional breast, so that's a fairly good amount). I sent DS to daycare with a 3oz bottle for the morning, then I nurse him at lunch, and then a 4oz bottle for the afternoon. Well, I just finished my first pumping session of the day and got 2oz total. It had been 3 hours since he last nursed! So now I am worried I won't be able to keep up. I have about 10-12oz stored at home and that's it... what am I going to do? Please tell me it will improve....