I also take a DHA oil supplement. I take Minami, which is a newer brand from Europe and hands down the cleanest fish oil made. It is so light and tasteless too. My last PG I took the Nordic Naturals one, but its processing still exposes the oil to heat, which is not great for oil.
I take Bone Strength from New Chapter as well, zinc, and starting in the 2nd trimester I will take Floradix. My iron count got really low last pregnancy.
The thing that bothers me about prenatal one a days is that your cells can only assimilate a certain amount of a nutrient at one time, you reach something called cell saturation. When you only take your supplement once a day- you aren't getting close to what is on the label. You get a fraction of it, depending on what your cell can hold and the efficiency of your body's assimilation process. The baby is constantly growing, so you really need a more steady stream of nutrients.
In a perfect world we would get all the nutrients we need from food, but we can't always eat like we would like to, afford organic produce, and even when we try our best the soil has been so depleted foods don't pack the nutritional punch they did 50 years ago.