When to buy new bras after breast augmentation?

For those of you who had breast augmentation, how long before you were buying new bras? Or did you know what size you would be?

I have read from others to wait a couple of months. My doctor says that at 3 months out, I should pretty much be where I will be. That said, I am 2 weeks out as of yesterday and I did buy 1 bra that wasn't a sports bra because the sports bra straps showed with most of my work clothes. If my size changes, so be it. I didn't have much to wear that worked with the sports bra. I did buy a 38 band because the 36 I wore pre-surgery just felt too tight after a 9 hour day of work. End result, I was hoping for a D. That's what I bought for now. I didn't try a DD, but wouldn't be surprised if it would fit now since I think I'm still a little swollen. In a couple of months, I'll get properly measured and splurge on a few good bras. If you are looking for something comfy in the meantime, Bali has one with a really soft band - no underwire - I paid about $20 at sears for it.