I am normally a modest 12B. Atm with feeding twins I'm an 18C in the brand of nursing bra I prefer (Joanne, from Best & Less, very soft & comfy as I wear them 24hrs), but the size difference is enormous. I could probably go a bit bigger size as the cleavage is a little uncomfortable, especially in this heat. I could do with some separation.

I have the biggest boobs in the universe & I can hardly stand up straight, lol. But I know I will go back to my nice little B cup after my babies are weaned.

I tend to need at least 2 sizes to get me through a pregnancy and then through lactation. In late pg & early feeding you're huge, then when they start solids you go back to the smaller size you bought in earlier pg.

And I reckon you need at least 4 in each size, as you're always wearing them and always washing them.