another big BB woman here. I went from E before I fell pg to F once I was pg to G when BF'ing number 2. I went back to E or F afterwards, but really I just keep wearing my mat bras as they are so comfy. My mum gave me some non mat, no u/wire bras, she grew out of and I've been wearing them a lot of the time (My Mat bras are now a little ratty after 2 bubs and into the 3rd pgcy).
Once bub is here, I'll invest in a new mat bra or two and be fitted again. Didn't see the point of doing it before as my bbs grow quite a bit bigger during BF'ing.