you usually go up a band size for the first few wks after surgery, so i think you should be in a 34.
your sports bra shouldnt be so tight that it leaves marks on your boobs, so i would go for the 34DD bra for now
i had the exact same stats as you with my first ba 7yrs ago, and i wore a 34E sports bra, then when they settled, i ended up a 32DD