supplements in pregnancy

hi, I have been doing tons of research on how to supplement nutrients during pregnancy as a vegan. i am taking a prenatal that has Dha, and bought 1200 mg Calcium with D3, 1000 mcg B12, and 65mg iron. however, I am nervous and also don't want to take too much of anything. my prenatal pill already has everything listed above, in smaller amounts, except the D3. it has 200mg Calcium, 25mcg B12, 30mg Iron. this is my first pregnancy... please give me some advice on supplements and what I should be focused on. thank you ladies.