DHA supplements?

Ann Marie • 35, Boston area. I have a 2-year-old son, pregnant with my second, due July 2018
Hi, not sure if this is the appropriate group to post this question, but seeing as I'm over 30 and many other groups are full of young girls/women with few nutritional concerns...
​Do any of you take DHA/omega3 supplements while TTC or during pregnancy? I'm TTC for the first time (32 yrs old), and I'm a vegetarian. I know veg diets can be low in omegas, so I'm considering taking a vegetarian DHA/omega3 pill in addition to my prenatal one-a-day vitamin. Is this common to take, or does it seem like overkill?