Not enough breast milk?

Kimberly
I had my daughter a week ago and she wants to be attached to my boobs all the time. I'm worried it's because my body isn't producing enough milk for her. I'll feed her for 30 mins (both sides) and she still seems hungry. I've been supplementing after each feeding but I'm worried because I'm going to returning to school in 3 weeks and would like to be able to pump. Anybody else go through this?