my boobs jumped up 7 sizes during my pregnancy, which is high I gather from asking around. Usually 2-3 sizes is normal.
I was a 34DDD pre-DS (altho I found 36DD to be more comfy since I have wide boobs and easier to obtain, they were a tad loose in the band...grr...)
By er, 12w I was wearing a 36DDD, which I wore again around 9m postpartum.
(I nursed until he was 2)
before my son was born, I'd wager I was a 36H, and after he was born the 36J i'd bought was too small for a couple weeks.
The H fit me around 4-6w PP, until about 5m or so...then I dropped again...
I've been telling breastfeeding moms-to-be on my support group to buy nursing bras at 36+ weeks. Whatever size you are wearing just before birth will be the size you will probably need after and for several months.

Unfortunately for me, finding nursing bras AT ALL is a challenge. Things like bravado arn't supportive enough for me anyways (I have a very short torso and prefer to hike the girls up high!) but usually if they are big enough for the boobs, they are FAR too big in the band *sigh*
Anyways, buy REGULAR but stretchy bras (if you can bear it...lol...I can't!) NOW, and you will use them again much later on

I'd buy several nursing bras around 36+ weeks, the later the better

and ATLEAST one stretchy sleep/nursing bra type deal. For me I was actually able to wear a old navy/target maternity tank, which gave enough support and held in breastpads, but gave me the dreaded uniboob

Worked for sleeping though!
Personally, i'm praying like hell that they don't get THAT big again...
Any other nursing moms jump up crazy sizes with their first? hope??
