I have been pumping since I've been back to work, which was right for me. I did experience some decrease in my supply when my son turned 4 months about 2 weeks ago, so I started mixing in some formula. Also, sometimes I only get to pump once during the day because of work circumstances and it worried me about my supply, but actually, as long as I breastfeed him when I get home and during the night and in the morning, my milk has always come back. Also, when it went really low, I tried drinking an herbal tea from GNC called 'mother's milk' and it really helped. You can buy the herbs that are in the tea as supplements (fenugreek and blessed thistle), but I was worried about taking a lot of the herb supplements because they can decrease the effectiveness of oral contraceptives (yikes! - I'm not ready to play around with that!), so I just drink the tea. Also, I didn't know you could buy this, but a person at Vitamin World told me about it after I was leary of the herb/ birth control thing. She told me to try taking Colostrum. It's used for the majority of people as an immune system enhancement, but for lactating women it helps milk production - it did! I take the colostrum with my pre-natals and DHA everyday. That's what worked for me. Hope I helped!