Nursing mamas that are pregnant

Hey all, currently im nursing and pumping for my 10 month old daughter. I am currently 11 weeks pregnant with my next baby and notices that my milk supply has decreased a lot. I used to make 4- 6 oz bottles a day no problem but now I can barely make two. I'm working full time so I'm trying to get my sessions in before, during and after but I'm barely scraping by. Is this normal you think? I'm just trying to make it to a year for my daughter but not sure if I'm gonna actually make it.