For what's it worth, I stressed about this same issue when I was pregnant and never ended up really using the nursing bras I bought. I would maybe have a cheap, comfortable one on-hand for the first week or two after your baby is born. But I LIVED in my nursing tanks (still do, and my son is over 9 months old). Most of the nursing bras I bought just never really fit me quite right. Throughout the early months of BFing, I found that my body/boob size just changed so much while my milk supply was regulating, I was losing baby weight, even my rib cage seemed to get smaller over time, etc., so this all affected how bras fit me. But the nursing tanks were heavenly and much more forgiving. I ended up buying a bunch at Target about 2 weeks postpartum when I could actually try them on, and then I just wore them 24/7. They are great because they can act like tanks that you would wear under cardigans, etc., but then you don't have to fumble much with your clothing when you are out. And at home, when I wasn't just topless the first few weeks due to sore nipples, I found that wearing the tanks kept me warm but gave me easy access. In my opinion, I don't know if it is all that possible to find the perfect-fitting nursing bra when you are still pregnant.