If you are vegetarian and you don’t want to eat fish or take fish oil, DHA that comes from algae might be a good option for you. This is one of the only plant-based options that is vegan, non-toxic and will raise your blood and breast milk DHA levels. There are other plant-based omega-3 sources like flax, walnuts and chia but they contain an omega-3 called alpha linolenic acid (ALA), which is healthy but it won’t raise your omega-3 DHA levels in blood and breast milk. So during pregnancy and postpartum it is important to take preformed DHA in an algal supplement if you are vegetarian.
Here is a helpful video.