When I was pg with #1 I went and got fitted at Myer or DJ (can't remember now) but they are free. I think a lot of bra shops offer free fittings. I went at about 16wks and hadn't changed much, I bought maybe 2 mat bras which was lucky cause after my milk came in I went from a pre pg 12B - 14B/C(at 16wks) - 14DD (after birth)

This time around I needed bigger bras so bought maternity and went for abut a 16D but I will wait until BF setles down before I buy any more. Trade secret and Target have some good cheap mat bras and I even found some that are t-shirt bras which are great for extra leakage protection and for thos high beaming occasions