Nursing shirts and bra advice

B

Nursing shirts - is it like maternity clothes where you buy your pre maternity size? Also do you feel like their necessary Or can i just pull up my normal shirt and nurse like that?

For nursing bras im 31 weeks and my boobs didnt grow that much. I want to get a few nursing bras, im assuming my boobs will grow alot more once my milk comes in.. How should i know what size to buy? I was a 32b before pregnancy, i probably would be a 34c right now.