How to save my supply

St

My son is 7 months and exclusivley breastfed since birth. I found out I'm pregnant last week and my milk is taking a hit. I'm eating oatmeal with flax seed every morning, eating boobie bites with brewers yeast all day, I increased my caloric intake and am pounding the water (reg and coconut water). Nothing is helping. I'm power pumping after my son nurses and hes even started cluster feeding again to get enough milk. I don't know what else I can do that's safe during pregnancy. I love nursing, my son loves nursing, I'm not ready for it to end. Any tips would be greatly appreciated!