I initially brought a couple of cheap nursing bras at Target before giving birth and wasn't sure about my size. Its tricky to figure out what your size will be until the milk fully comes in and then settles to a normal level (took about a month after birth). The bras I bought before giving birth did not fit right; I saw this bra had good reviews and I was excited at their selection of sizes. Which was perfect for someone like me who is small around the back but has a large cup size. It would have been nearly impossible to find a 36F in the stores. Make sure to measure yourself and follow the sizing guide.