So long as you are getting the folic acid and arguably vitamin D3, you are all good. You don't need to take a multivitamin unless you want too. There's a fair chunk of evidence that we don't absorb tablet forms of vitamins very well at all. It's better to aim for a good diet! I did buy some Seven Sea's prenatals but I couldn't swallow them, they just made me sick! So I took stand alone folic acid & vitamin d3 capsules, which were much easier to swallow! I still take those now actually although I don't think you need extra folic acid past the first trimester.
I'd be willing to bet the branded prenatals are almost identical to own brand. It's crazy how much extra we spend on branded medication when it's all the same if you look at the ingredients! Like Nurofen - it's twice the price of a non brand ibrubofen but literally identical in medicine content..!