There are lingerie designs for almost anything nowadays, so it didn't surprise me when researching on a personal level, that there are nursing sports bras. Could I just buy my old sports bra style in a bigger size? A style I know that works.
I asked the website Boobydoo more information about this:
Q: Can I wear a normal sports bra whilst breastfeeding?
Boobydo: I realise there is fluctuation of breast size during breast feeding, and you need lots of support, but not too much compression. So maybe an encapsulation style bra might be better for you at this moment. (Compression bras are made from stretch fabric which holds your breasts close to your chest wall to minimise the bounce. Encapsulation bras have separate cups which support your breasts from beneath).
I'd recommend the Jubralee bra which goes up to an E cup.