Hello,
I was vegetarian for 13 years and vegan now for one year. I bought a vegan pregnancy book to help and read a lot online. It really depends on your diet choices. Are you eating a well balanced diet full of leafy greens, fruits, vegetables, nuts, seeds, legumes, beans and grains? If so you should be healthy! I am also taking a whole food prenatal vitamin. Protein isn't the biggest concern for vegans and vegetarians as it's in everything.
B12 and iron are often more deficient. A good prenatal will take care of that. And dark leafy greens have a lot of iron and calcium. Two complete protiens (all 9 essential amino acids) are avocado and quinoa.
I have been doing terrible with a varied diet due to nausea and laziness! Now I am almost 12 weeks and feeling much better. I am able to eat salad again =).