You can never have enough...

Breastmilk. I have like 10 bottles in the fridge, each with 4-5 oz ready to go. She'll eat the first two or three while I'm gone tomorrow at work, and I'll pump twice at work to replace what she had. However, if she eats three times while I'm gone, then I'll only have 9 bottles in my stash. Do you see my problem? I'm not one of those who pumps records 13 oz in a sitting, nor am I a "milk dud" who pumps 1 oz in 20 minutes. I would consider myself average.
If I pump to replace a feeding, aka I'm not with my beautiful daughter, I get the 4-5 oz that she would typically consume. If I try and pump between feedings or at night after she's gone to bed, I might get 2-3 oz depending. The hard thing is, I never know if what I'm doing it right. Obviously, I know I'm over thinking things, because as long as my baby is fed and happy, things are ultimately ok, which they are.
For example, yesterday I fed her at 8:00 am. She didn't seem super hungry, so I pumped to get less full at like 9:15. Then, I had to leave at like 10:20. So I left, and daddy fed her with a bottle of breastmilk at 10:45. I got home at 12:30 pm. I had to shower (was sweaty from teaching my class) and eat the lunch my hubby had to lovingly prepared for me. By this time is was probably 1 pm. I knew she would be eating again in 30-45 minutes. So, to pump or not to pump...that is the question. I was full having not fed or pumped in 4 hours, but didn't want to be empty when it came time to nurse her. If I waited, I knew I was skipping a feeding etc. They (lactation specialist) say that you are never quite empty, but there's definitely times when I have a feeling not much is coming out. So, I hemmed and hawed about what to do. Ended up pumping for a short time, equaling 3 oz and then feeding her when she work up at like 1:30.
I did what I thought was best, but no one explains these things, not even the books I so diligently rely on. So, when she ate at 4:20 pm, I ended up nursing her for almost an hour just to make up for it. Did she need to eat that long? No way. Was any milk coming out after the first 20 minutes? Probably not. Did I feel like I was doing something good for her? Yes, she was cozy, snuggled, half asleep, and helping my increase my milk production.