Get at least one stretchy one.
I was a 36A and had 375 high profile unders put in.
My PS thought I’d be a 36CC
I bought 36/38 C sportbras and some stretchy ones that are C/D.
And a macom in 36.
So far I’m 4 days PO and so swollen that everything is uncomfortable to wear.
The only thing I can comfortably wear is a post surgery bra with built in ice pockets (bliss) that came from a company selling them on eBay. It’s really stretchy material but supportive and is very comfortable.
So I’d say buy at least 1 bra that is much bigger than you think you will need.