Low supply. Please help.

I have been trying to breastfeeding for 3 weeks. My got around 1.5 to 2 oz of milk supply when I pumped before feeding and only half an ounce after breastfeed. My baby eat around 3 to 3.5 oz each feeding. I have been supplemented with formula. I want to know if Anybody else has the same problem. And do your milk supply increase to satisfy your baby need. I have to drop her with the day care in soon and i was worry about my milk supply that i have to provide to day care. I tried mother milk tea and fenugreek