Milk Supply

One of the biggest mysteries for breast feeding moms is how do I know my baby is having enough milk? Joaquin is quite a big eater. I spend half of my day feeding him and the other half worrying about whether he is getting enough milk. He was pretty good for the first 3 weeks, eating already on a four-hour cycle. But the last two weeks, his schedule has been a bit out of whack (ever since I started reading Gina Ford and wanted to train him). He was nursing every 2-3 hours the day my mother left and also the day Jaime's mom & dad left. We thought it was because he sensed the departure of his caretakers and needed to be nursed more to feel secure. However, the last two days, he has been demanding to eat every 2-3 hours again. I think I do have enough milk (as evidenced by constant wet and dirty nappies) but maybe he is just going through another growth spurt. I am downing 3 bottles of 1.5 liter water every day yet I can't seem to increase my supply to match Joaquin's ferocious appetite...