Pregnant and still nursing...milk supply going down. How do I get myself to supply more milk???

Cheryl
So I'm currently about 15 1/2 weeks pregnant and nursing my almost 11 month old baby. I've noticed my milk supply is dropping. I just tried to pump with my manual pump and with both I only got about 1  1/2- 1  3/4oz! I know she's getting more when I breastfeed but what can I do to get myself to produce more milk? I know I can give her regular milk after she turns one. I'd rather not give her formula if I don't need to. She still clearly likes to breastfeed. I'd like to breastfeed for a while longer at least even though it hurts. lol I'd appreciate any suggestions. Thanks!