You can certainly pump to increase your supply, although I can't pump so it never worked that way for me. Instead I used my LO like a pump. I feed from both sides when nursing, so when I want to increase for whatever reason I put my LO back on the first BB again after doing both sides. Sometimes I also offer the BB again an hour later. There are suppliments you can take like fenugreek tablets and blessed thistle, and a tea called "Mother's Milk" that I liked. I never took blessed thistle but fenugreek worked; you take three tablets three times a day until you smell like maple syrup. You shouldn't use that if you have worries about blood pressure, asthma, or diabetis, though. I eat oatmeal and drink Ovaltine (with malt) almost every day because a) they are good for you, and b) they help make good milk. Lots of rest will help, and plenty of water is vital. There are a few medications that you can get from your dr that will help if the other ways don't make a difference. You can also use breast compressions while nursing and pumping to make sure that you are getting out every drop; that will help cue your body to start producing more.
Early teething does suck, so hopefully that won't be a bother! My DS had his first teeth by 4.5 months and my DD is about to pop her first as well. Arg.
Posted as Claire did!