At about 8 weeks I bought 2 target cotton non underwire bras for $30 each. They have a wide elastic band under my bust and wide cotton straps and plenty of hooks. My normal size is a 16d and the berlei fitter that happened to be I store advised an 18 dd. I'm so glad I got them as I've now needed to use the looser hook and am almost filling the cup too.
I'll buy feeding bras later on but for most of my pg these will be just fine.