J.C.
Here is some info for you. There is a helpful chart...
http://www.askdrsears.com/html/2/t026900.asp#T026901
Also, when I had questions, I called the hospital where I delivered and talked with a lactation consultant. Don't know if this is an option.
Don't believe what you read about your milk drying up faster because you pump. My son is 16 months old. I could have pumped forever. I had a TON of milk because I pumped completely instead of only feeding (nursing) him what he needed. I have friends who pumped for the full year.
Good luck!