Tips on how to up my supply? Pls help..

Natalie • Married, mommy to a baby 🎀 & baby 🎀 #2 due July2020

My baby girl will be 9 months next week and I just found out Im pregnant (4w4d). I would like to continue to breastfeeding until my baby girl is 1. Last week I noticed my supply drop. I usually pump 13-16oz at work (9hours) but now Im only pumping 8-10oz. Baby girl drinks close to 15oz at childcare. I was lucky enough to build up a stash while on maternity leave, but Im now going through that stash real fast. Any tips on how to up my supply? I would love to continue breastfeeding for 3 more months. Please help! TIA