I normally take my pregnancy vitamins 2 hours after my iron tablets so the calcium in them doesn't affect the iron absorbing x
Ask your doctor, and check if your other vitamins contain omega 3 already..
However, omega 3 is crucial for brain development for your baby, so if you're deficient, you should probably take extra..
I don't know how vitamins affect each other, you have to ask your doctor or pharmacist about that.
Call your doctor... Thats the safest bet. Or call your pharmacists.