Milk may drop for many reasons. Think of anything that will redistribute the "energy" from making milk to more survival for the body needs. Like around periods (even if you're not menstruating); physical illness, even miner, body will priorities to "fix" the problem.
Any supplements or dietary changes, (when I eat unusual foods my body like"What was that?I need an extra minute.:) I learned for me works for quick milk production food that my body is most familiar with." If you dropped supplements it's natural for the body to adjust for few days.
Eating lot's of carbs helps! I used to be raw vegan :) Salads doesn't help make lot's of milk. (I heard some vegans successfully nursed, not me) So lot's of carbs is good. if your baby will start to have skin problems get rid of absolutely all dairy in your diet. Watch out for breads made with milk or butter (whole not-homogenized milk might be different story). Sorry, for navigate away, but I thought to mention just it in case.
Stress. Oh boy, I cant say enough about it. Stress doesn't have to be negative emotion, for me it's creative mind. More I strategically thinking, less milk I have.
Worried about not getting milk will do it to. Though it's more not letting down milk that leads eventually to less production. I used to use feeding time as caching up with my business on computer - big No-No.
I bought a best formula I could find and always had it in the house for my peace of mind, just in case I'm not gonna have not enough milk. It helped. I never used it.
Drink lot's of water. I heard it so many times,but what is a lot?, My lactation consultant believes that nursing woman should drink to thirst, sometime I feel like I'would gag if I drink any more. When I eat salty food like mexican(w/out cheese :) I drink so much more water, I produce much more milk. )
Eat, pump, feed baby, rest, repeat. 24/7
About pumping. Old fashion hand milk extraction works so much better for me then any pump. However, rounding back not good for letting down. I have to stop and relax many times. Also it was helpful to experiment with different ways to massage breast, apply moist heat, twist the nipples, not thinking about pumping while massaging ect. For me laying down while nursing was always much more relaxing = more milk. My daughter still sleeps with me and get most of her milk at night.
Little personal story:
I'm not that lucky woman who have lot's of milk. Plus my breast are half functioning due to implants surgery while back. When my daughter was born I was hopping to BF her at list 6 month. It wasn't easy, but I did it! Then I went to health research center to get a raw goat milk to make home made formula. The women who I talked to encouraged me to breastfeed solidly till one year old, explaining all the benefits for my daughter. The goal was to increase my milk supply. (Up to that day I used to take "more milk plus " and gain a lot of weight, well I didn't order supplements on time and was out of my magic pills that day. Oh, NO!). She sad: "Do You believe in God?"..."You need to lay down, drink plenty of water and know that God will provide milk for your baby just exactly as she need." I'm not religious person, but it made perfect sense to me. Well, I went that day home and follow "the instructions". My milk was floooaaating!!! Never took the pills again!
Hope it helped to you,